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view doc/disas_examples/arm64.aapcs.disas @ 497:cb19b2fe2422
- more disas examples to check behaviour of passing C++ non-trivial aggregates by value; they all behave the same, calling the copy ctor first, passing a pointer then
| author | Tassilo Philipp |
|---|---|
| date | Wed, 23 Mar 2022 15:24:31 +0100 |
| parents | 0fc22b5feac7 |
| children | fc614cb865c6 |
line wrap: on
line source
; #include <stdlib.h> ; ; void leaf_call(int b, int c, int d, int e, int f, int g, int h) ; { ; } ; ; void nonleaf_call(int a, int b, int c, int d, int e, int f, int g, int h) ; { ; /* use some local data */ ; *(char*)alloca(220) = 'L'; ; leaf_call(b, c, d, e, f, g, h); ; } ; ; int main() ; { ; nonleaf_call(0, 1, 2, 3, 4, 5, 6, 7); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 leaf_call: 0: ff 83 00 d1 sub sp, sp, #32 4: e0 1f 00 b9 str w0, [sp, #28] 8: e1 1b 00 b9 str w1, [sp, #24] c: e2 17 00 b9 str w2, [sp, #20] 10: e3 13 00 b9 str w3, [sp, #16] 14: e4 0f 00 b9 str w4, [sp, #12] 18: e5 0b 00 b9 str w5, [sp, #8] 1c: e6 07 00 b9 str w6, [sp, #4] 20: ff 83 00 91 add sp, sp, #32 24: c0 03 5f d6 ret nonleaf_call: 28: ff 83 04 d1 sub sp, sp, #288 ; | includes alloca()'d static space, already 2c: fc 83 00 f9 str x28, [sp, #256] ; | (unsure why r28 is preserved @@@) 30: fd 7b 11 a9 stp x29, x30, [sp, #272] ; | prolog 34: fd 43 04 91 add x29, sp, #272 ; | adjust/set frame pointer (since sp was modified first) 38: 88 09 80 52 mov w8, #76 ; 'L' -> w8 3c: a0 c3 1e b8 stur w0, [x29, #-20] ; in arg 0 -> local area (as temp store) 40: a1 83 1e b8 stur w1, [x29, #-24] ; in arg 1 -> local area (as temp store) 44: a2 43 1e b8 stur w2, [x29, #-28] ; in arg 2 -> local area (as temp store) 48: a3 03 1e b8 stur w3, [x29, #-32] ; in arg 3 -> local area (as temp store) 4c: a4 c3 1d b8 stur w4, [x29, #-36] ; in arg 4 -> local area (as temp store) 50: a5 83 1d b8 stur w5, [x29, #-40] ; in arg 5 -> local area (as temp store) 54: a6 43 1d b8 stur w6, [x29, #-44] ; in arg 6 -> local area (as temp store) 58: a7 03 1d b8 stur w7, [x29, #-48] ; in arg 7 -> local area (as temp store) 5c: e8 03 00 39 strb w8, [sp] ; place 'L' on top of stack (at alloca()'d addr) 60: a0 83 5e b8 ldur w0, [x29, #-24] ; arg 0 64: a1 43 5e b8 ldur w1, [x29, #-28] ; arg 1 68: a2 03 5e b8 ldur w2, [x29, #-32] ; arg 2 6c: a3 c3 5d b8 ldur w3, [x29, #-36] ; arg 3 70: a4 83 5d b8 ldur w4, [x29, #-40] ; arg 4 74: a5 43 5d b8 ldur w5, [x29, #-44] ; arg 5 78: a6 03 5d b8 ldur w6, [x29, #-48] ; arg 6 7c: e1 ff ff 97 bl #-124 ; return address -> r30/lr, and call 80: fd 7b 51 a9 ldp x29, x30, [sp, #272] ; | 84: fc 83 40 f9 ldr x28, [sp, #256] ; | 88: ff 83 04 91 add sp, sp, #288 ; | epilog 8c: c0 03 5f d6 ret ; | main: 90: ff 83 00 d1 sub sp, sp, #32 ; | 94: fd 7b 01 a9 stp x29, x30, [sp, #16] ; | prolog 98: fd 43 00 91 add x29, sp, #16 ; | 9c: 08 00 80 52 mov w8, #0 ; clearing r8 (indirect result location pointer) a0: e1 03 00 32 orr w1, wzr, #0x1 ; arg 1 a4: e2 03 1f 32 orr w2, wzr, #0x2 ; arg 2 a8: e3 07 00 32 orr w3, wzr, #0x3 ; arg 3 ac: e4 03 1e 32 orr w4, wzr, #0x4 ; arg 4 b0: a5 00 80 52 mov w5, #5 ; arg 5 b4: e6 07 1f 32 orr w6, wzr, #0x6 ; arg 6 b8: e7 0b 00 32 orr w7, wzr, #0x7 ; arg 7 bc: bf c3 1f b8 stur wzr, [x29, #-4] ; unsure... store a zero in local area@@@ c0: e0 03 08 2a mov w0, w8 ; arg 0 (= 0 set in w8, above) c4: e8 0b 00 b9 str w8, [sp, #8] ; temp storing 0 in local area c8: d8 ff ff 97 bl #-160 ; return address -> r30/lr, and call cc: e0 0b 40 b9 ldr w0, [sp, #8] ; return value (unsure why not just using immediate @@@) d0: fd 7b 41 a9 ldp x29, x30, [sp, #16] ; | d4: ff 83 00 91 add sp, sp, #32 ; | epilog d8: c0 03 5f d6 ret ; | ; ---------- same with more args so stack is also used ----------> ; #include <stdlib.h> ; ; void leaf_call(int b, int c, int d, int e, int f, int g, int h, int i, int j) ; { ; } ; ; void nonleaf_call(int a, int b, int c, int d, int e, int f, int g, int h, int i, int j) ; { ; /* use some local data */ ; *(char*)alloca(220) = 'L'; ; leaf_call(b, c, d, e, f, g, h, i, j); ; } ; ; int main() ; { ; nonleaf_call(0, 1, 2, 3, 4, 5, 6, 7, 8, 9); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff c3 00 d1 sub sp, sp, #48 4: e8 33 40 b9 ldr w8, [sp, #48] 8: e0 2f 00 b9 str w0, [sp, #44] c: e1 2b 00 b9 str w1, [sp, #40] 10: e2 27 00 b9 str w2, [sp, #36] 14: e3 23 00 b9 str w3, [sp, #32] 18: e4 1f 00 b9 str w4, [sp, #28] 1c: e5 1b 00 b9 str w5, [sp, #24] 20: e6 17 00 b9 str w6, [sp, #20] 24: e7 13 00 b9 str w7, [sp, #16] 28: e8 0f 00 b9 str w8, [sp, #12] 2c: ff c3 00 91 add sp, sp, #48 30: c0 03 5f d6 ret 0000000000000034 nonleaf_call: 34: ff 03 05 d1 sub sp, sp, #320 ; | includes alloca()'d static space, already 38: fc 93 00 f9 str x28, [sp, #288] ; | (unsure why r28 is preserved @@@) 3c: fd 7b 13 a9 stp x29, x30, [sp, #304] ; | prolog 40: fd c3 04 91 add x29, sp, #304 ; / adjust/set frame pointer (since sp was modified first) 44: a8 13 40 b9 ldr w8, [x29, #16] ; \ 48: a9 1b 40 b9 ldr w9, [x29, #24] ; | in args 8,9 from prev frame's param area -> regs, no we have args 0-9 all in r0-r9 4c: 8a 09 80 52 mov w10, #76 ; 'L' -> w10 50: a0 c3 1e b8 stur w0, [x29, #-20] ; | 54: a1 83 1e b8 stur w1, [x29, #-24] ; | 58: a2 43 1e b8 stur w2, [x29, #-28] ; | 5c: a3 03 1e b8 stur w3, [x29, #-32] ; | 60: a4 c3 1d b8 stur w4, [x29, #-36] ; | ... in args 0,1,2,3,4,5,6,7,8,9 -> temp space in local area ... 64: a5 83 1d b8 stur w5, [x29, #-40] ; | 68: a6 43 1d b8 stur w6, [x29, #-44] ; | 6c: a7 03 1d b8 stur w7, [x29, #-48] ; | 70: a8 c3 1c b8 stur w8, [x29, #-52] ; | 74: a9 83 1c b8 stur w9, [x29, #-56] ; | 78: ea 43 00 39 strb w10, [sp, #16] ; 'L' -> local area (alloca()'d memory) 7c: a0 83 5e b8 ldur w0, [x29, #-24] ; arg 0 80: a1 43 5e b8 ldur w1, [x29, #-28] ; arg 1 84: a2 03 5e b8 ldur w2, [x29, #-32] ; arg 2 88: a3 c3 5d b8 ldur w3, [x29, #-36] ; arg 3 8c: a4 83 5d b8 ldur w4, [x29, #-40] ; arg 4 90: a5 43 5d b8 ldur w5, [x29, #-44] ; arg 5 94: a6 03 5d b8 ldur w6, [x29, #-48] ; arg 6 98: a7 c3 5c b8 ldur w7, [x29, #-52] ; arg 7 9c: a8 83 5c b8 ldur w8, [x29, #-56] ; arg 8 -> w8, and ... a0: eb 03 00 91 mov x11, sp ; ... with help of x11 (why?) ... a4: 68 01 00 b9 str w8, [x11] ; ... "pushed" onto to of stack a8: d6 ff ff 97 bl #-168 <leaf_call> ; return address -> r30/lr, and call ac: fd 7b 53 a9 ldp x29, x30, [sp, #304] ; | b0: fc 93 40 f9 ldr x28, [sp, #288] ; | b4: ff 03 05 91 add sp, sp, #320 ; | epilog b8: c0 03 5f d6 ret ; | 00000000000000bc main: bc: ff c3 00 d1 sub sp, sp, #48 ; | c0: fd 7b 02 a9 stp x29, x30, [sp, #32] ; | prolog c4: fd 83 00 91 add x29, sp, #32 ; | c8: 08 00 80 52 mov w8, #0 ; clearing r8 (indirect result location pointer) cc: e1 03 00 32 orr w1, wzr, #0x1 ; arg 1 d0: e2 03 1f 32 orr w2, wzr, #0x2 ; arg 2 d4: e3 07 00 32 orr w3, wzr, #0x3 ; arg 3 d8: e4 03 1e 32 orr w4, wzr, #0x4 ; arg 4 dc: a5 00 80 52 mov w5, #5 ; arg 5 e0: e6 07 1f 32 orr w6, wzr, #0x6 ; arg 6 e4: e7 0b 00 32 orr w7, wzr, #0x7 ; arg 7 e8: e9 03 1d 32 orr w9, wzr, #0x8 ; arg 8 -> r9 ec: 2a 01 80 52 mov w10, #9 ; arg 9 -> r10 f0: bf c3 1f b8 stur wzr, [x29, #-4] ; unsure... store a zero in local area@@@ f4: e0 03 08 2a mov w0, w8 ; arg 0 (= 0 set in w8, above) f8: eb 03 00 91 mov x11, sp ; use sp in x11 (why?), to ... fc: 69 01 00 b9 str w9, [x11] ; ... place arg 8 on top of stack 100: eb 03 00 91 mov x11, sp ; use sp in x11 (why?), to ... (set again, pointlessly) 104: 6a 09 00 b9 str w10, [x11, #8] ; ... place arg 9 on stack (next to arg 8) 108: a8 83 1f b8 stur w8, [x29, #-8] ; temp storing 0 in local area @@@ why? 10c: ca ff ff 97 bl #-216 <nonleaf_call> ; return address -> r30/lr, and call 110: a0 83 5f b8 ldur w0, [x29, #-8] ; | 114: fd 7b 42 a9 ldp x29, x30, [sp, #32] ; | 118: ff c3 00 91 add sp, sp, #48 ; | epilog 11c: c0 03 5f d6 ret ; | ; ---------- for spilling ----------> ; #include <stdlib.h> ; #include <stdarg.h> ; ; void leaf_call(int b, int c, int d, int e, int f, int g, int h, int i, int j) ; { ; } ; ; void nonleaf_call(int a, ...) ; { ; int b,c,d,e,f,g,h,i,j; ; va_list ap; ; va_start(ap, a); ; b = va_arg(ap, int); ; c = va_arg(ap, int); ; d = va_arg(ap, int); ; e = va_arg(ap, int); ; f = va_arg(ap, int); ; g = va_arg(ap, int); ; h = va_arg(ap, int); ; i = va_arg(ap, int); ; j = va_arg(ap, int); ; ; /* use some local data */ ; *(char*)alloca(220) = 'L'; ; leaf_call(b, c, d, e, f, g, h, i, j); ; } ; ; int main() ; { ; nonleaf_call(0, 1, 2, 3, 4, 5, 6, 7, 8, 9); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff c3 00 d1 sub sp, sp, #48 4: e8 33 40 b9 ldr w8, [sp, #48] 8: e0 2f 00 b9 str w0, [sp, #44] c: e1 2b 00 b9 str w1, [sp, #40] 10: e2 27 00 b9 str w2, [sp, #36] 14: e3 23 00 b9 str w3, [sp, #32] 18: e4 1f 00 b9 str w4, [sp, #28] 1c: e5 1b 00 b9 str w5, [sp, #24] 20: e6 17 00 b9 str w6, [sp, #20] 24: e7 13 00 b9 str w7, [sp, #16] 28: e8 0f 00 b9 str w8, [sp, #12] 2c: ff c3 00 91 add sp, sp, #48 30: c0 03 5f d6 ret 0000000000000034 nonleaf_call: 34: fc 4f be a9 stp x28, x19, [sp, #-32]! ; | 38: fd 7b 01 a9 stp x29, x30, [sp, #16] ; | 3c: fd 43 00 91 add x29, sp, #16 ; | prolog 40: ff 83 07 d1 sub sp, sp, #480 ; | 44: f3 03 00 91 mov x19, sp 48: 67 56 80 3d str q7, [x19, #336] ; | 4c: 66 52 80 3d str q6, [x19, #320] ; | 50: 65 4e 80 3d str q5, [x19, #304] ; | 54: 64 4a 80 3d str q4, [x19, #288] ; | 58: 63 46 80 3d str q3, [x19, #272] ; | spill all flot regs (on top of spilled integers, below 5c: 62 42 80 3d str q2, [x19, #256] ; | 60: 61 3e 80 3d str q1, [x19, #240] ; | 64: 60 3a 80 3d str q0, [x19, #224] ; / 68: a7 03 1a f8 stur x7, [x29, #-96] ; \ 6c: a6 83 19 f8 stur x6, [x29, #-104] ; | 70: a5 03 19 f8 stur x5, [x29, #-112] ; | 74: a4 83 18 f8 stur x4, [x29, #-120] ; | spill integer args (adjacent to prev frame's param area) 78: a3 03 18 f8 stur x3, [x29, #-128] ; | note: only needed ones are spilled 7c: a2 83 17 f8 stur x2, [x29, #-136] ; | 80: a1 03 17 f8 stur x1, [x29, #-144] ; | 84: a0 c3 1e b8 stur w0, [x29, #-20] 88: e0 63 19 32 orr w0, wzr, #0xffffff80 8c: a0 43 1c b8 stur w0, [x29, #-60] 90: e0 06 80 12 mov w0, #-56 94: a0 03 1c b8 stur w0, [x29, #-64] 98: 61 82 03 91 add x1, x19, #224 9c: 21 00 02 91 add x1, x1, #128 a0: a1 83 1b f8 stur x1, [x29, #-72] a4: a1 43 02 d1 sub x1, x29, #144 a8: 21 e0 00 91 add x1, x1, #56 ac: a1 03 1b f8 stur x1, [x29, #-80] b0: a1 43 00 91 add x1, x29, #16 b4: a1 83 1a f8 stur x1, [x29, #-88] b8: a1 63 01 d1 sub x1, x29, #88 bc: 21 60 00 91 add x1, x1, #24 c0: a0 03 5c b8 ldur w0, [x29, #-64] c4: e8 03 00 2a mov w8, w0 c8: 61 6e 00 f9 str x1, [x19, #216] cc: 68 d6 00 b9 str w8, [x19, #212] d0: e0 01 f8 36 tbz w0, #31, #60 <nonleaf_call+0xd8> d4: 01 00 00 14 b #4 <nonleaf_call+0xa4> d8: 68 d6 40 b9 ldr w8, [x19, #212] dc: 09 21 00 11 add w9, w8, #8 e0: 6a 6e 40 f9 ldr x10, [x19, #216] e4: 49 01 00 b9 str w9, [x10] e8: 29 01 00 71 subs w9, w9, #0 ec: 69 d2 00 b9 str w9, [x19, #208] f0: ec 00 00 54 b.gt #28 <nonleaf_call+0xd8> f4: 01 00 00 14 b #4 <nonleaf_call+0xc4> f8: a8 03 5b f8 ldur x8, [x29, #-80] fc: 69 d6 40 b9 ldr w9, [x19, #212] 100: 08 c1 29 8b add x8, x8, w9, sxtw 104: 68 66 00 f9 str x8, [x19, #200] 108: 06 00 00 14 b #24 <nonleaf_call+0xec> 10c: a8 83 5a f8 ldur x8, [x29, #-88] 110: 09 21 00 91 add x9, x8, #8 114: a9 83 1a f8 stur x9, [x29, #-88] 118: 68 66 00 f9 str x8, [x19, #200] 11c: 01 00 00 14 b #4 <nonleaf_call+0xec> 120: 68 66 40 f9 ldr x8, [x19, #200] 124: 09 01 40 b9 ldr w9, [x8] 128: a9 83 1e b8 stur w9, [x29, #-24] 12c: a8 63 01 d1 sub x8, x29, #88 130: 08 61 00 91 add x8, x8, #24 134: a9 03 5c b8 ldur w9, [x29, #-64] 138: ea 03 09 2a mov w10, w9 13c: 68 62 00 f9 str x8, [x19, #192] 140: 6a be 00 b9 str w10, [x19, #188] 144: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x14c> 148: 01 00 00 14 b #4 <nonleaf_call+0x118> 14c: 68 be 40 b9 ldr w8, [x19, #188] 150: 09 21 00 11 add w9, w8, #8 154: 6a 62 40 f9 ldr x10, [x19, #192] 158: 49 01 00 b9 str w9, [x10] 15c: 29 01 00 71 subs w9, w9, #0 160: 69 ba 00 b9 str w9, [x19, #184] 164: ec 00 00 54 b.gt #28 <nonleaf_call+0x14c> 168: 01 00 00 14 b #4 <nonleaf_call+0x138> 16c: a8 03 5b f8 ldur x8, [x29, #-80] 170: 69 be 40 b9 ldr w9, [x19, #188] 174: 08 c1 29 8b add x8, x8, w9, sxtw 178: 68 5a 00 f9 str x8, [x19, #176] 17c: 06 00 00 14 b #24 <nonleaf_call+0x160> 180: a8 83 5a f8 ldur x8, [x29, #-88] 184: 09 21 00 91 add x9, x8, #8 188: a9 83 1a f8 stur x9, [x29, #-88] 18c: 68 5a 00 f9 str x8, [x19, #176] 190: 01 00 00 14 b #4 <nonleaf_call+0x160> 194: 68 5a 40 f9 ldr x8, [x19, #176] 198: 09 01 40 b9 ldr w9, [x8] 19c: a9 43 1e b8 stur w9, [x29, #-28] 1a0: a8 63 01 d1 sub x8, x29, #88 1a4: 08 61 00 91 add x8, x8, #24 1a8: a9 03 5c b8 ldur w9, [x29, #-64] 1ac: ea 03 09 2a mov w10, w9 1b0: 68 56 00 f9 str x8, [x19, #168] 1b4: 6a a6 00 b9 str w10, [x19, #164] 1b8: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x1c0> 1bc: 01 00 00 14 b #4 <nonleaf_call+0x18c> 1c0: 68 a6 40 b9 ldr w8, [x19, #164] 1c4: 09 21 00 11 add w9, w8, #8 1c8: 6a 56 40 f9 ldr x10, [x19, #168] 1cc: 49 01 00 b9 str w9, [x10] 1d0: 29 01 00 71 subs w9, w9, #0 1d4: 69 a2 00 b9 str w9, [x19, #160] 1d8: ec 00 00 54 b.gt #28 <nonleaf_call+0x1c0> 1dc: 01 00 00 14 b #4 <nonleaf_call+0x1ac> 1e0: a8 03 5b f8 ldur x8, [x29, #-80] 1e4: 69 a6 40 b9 ldr w9, [x19, #164] 1e8: 08 c1 29 8b add x8, x8, w9, sxtw 1ec: 68 4e 00 f9 str x8, [x19, #152] 1f0: 06 00 00 14 b #24 <nonleaf_call+0x1d4> 1f4: a8 83 5a f8 ldur x8, [x29, #-88] 1f8: 09 21 00 91 add x9, x8, #8 1fc: a9 83 1a f8 stur x9, [x29, #-88] 200: 68 4e 00 f9 str x8, [x19, #152] 204: 01 00 00 14 b #4 <nonleaf_call+0x1d4> 208: 68 4e 40 f9 ldr x8, [x19, #152] 20c: 09 01 40 b9 ldr w9, [x8] 210: a9 03 1e b8 stur w9, [x29, #-32] 214: a8 63 01 d1 sub x8, x29, #88 218: 08 61 00 91 add x8, x8, #24 21c: a9 03 5c b8 ldur w9, [x29, #-64] 220: ea 03 09 2a mov w10, w9 224: 68 4a 00 f9 str x8, [x19, #144] 228: 6a 8e 00 b9 str w10, [x19, #140] 22c: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x234> 230: 01 00 00 14 b #4 <nonleaf_call+0x200> 234: 68 8e 40 b9 ldr w8, [x19, #140] 238: 09 21 00 11 add w9, w8, #8 23c: 6a 4a 40 f9 ldr x10, [x19, #144] 240: 49 01 00 b9 str w9, [x10] 244: 29 01 00 71 subs w9, w9, #0 248: 69 8a 00 b9 str w9, [x19, #136] 24c: ec 00 00 54 b.gt #28 <nonleaf_call+0x234> 250: 01 00 00 14 b #4 <nonleaf_call+0x220> 254: a8 03 5b f8 ldur x8, [x29, #-80] 258: 69 8e 40 b9 ldr w9, [x19, #140] 25c: 08 c1 29 8b add x8, x8, w9, sxtw 260: 68 42 00 f9 str x8, [x19, #128] 264: 06 00 00 14 b #24 <nonleaf_call+0x248> 268: a8 83 5a f8 ldur x8, [x29, #-88] 26c: 09 21 00 91 add x9, x8, #8 270: a9 83 1a f8 stur x9, [x29, #-88] 274: 68 42 00 f9 str x8, [x19, #128] 278: 01 00 00 14 b #4 <nonleaf_call+0x248> 27c: 68 42 40 f9 ldr x8, [x19, #128] 280: 09 01 40 b9 ldr w9, [x8] 284: a9 c3 1d b8 stur w9, [x29, #-36] 288: a8 63 01 d1 sub x8, x29, #88 28c: 08 61 00 91 add x8, x8, #24 290: a9 03 5c b8 ldur w9, [x29, #-64] 294: ea 03 09 2a mov w10, w9 298: 68 3e 00 f9 str x8, [x19, #120] 29c: 6a 76 00 b9 str w10, [x19, #116] 2a0: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x2a8> 2a4: 01 00 00 14 b #4 <nonleaf_call+0x274> 2a8: 68 76 40 b9 ldr w8, [x19, #116] 2ac: 09 21 00 11 add w9, w8, #8 2b0: 6a 3e 40 f9 ldr x10, [x19, #120] 2b4: 49 01 00 b9 str w9, [x10] 2b8: 29 01 00 71 subs w9, w9, #0 2bc: 69 72 00 b9 str w9, [x19, #112] 2c0: ec 00 00 54 b.gt #28 <nonleaf_call+0x2a8> 2c4: 01 00 00 14 b #4 <nonleaf_call+0x294> 2c8: a8 03 5b f8 ldur x8, [x29, #-80] 2cc: 69 76 40 b9 ldr w9, [x19, #116] 2d0: 08 c1 29 8b add x8, x8, w9, sxtw 2d4: 68 36 00 f9 str x8, [x19, #104] 2d8: 06 00 00 14 b #24 <nonleaf_call+0x2bc> 2dc: a8 83 5a f8 ldur x8, [x29, #-88] 2e0: 09 21 00 91 add x9, x8, #8 2e4: a9 83 1a f8 stur x9, [x29, #-88] 2e8: 68 36 00 f9 str x8, [x19, #104] 2ec: 01 00 00 14 b #4 <nonleaf_call+0x2bc> 2f0: 68 36 40 f9 ldr x8, [x19, #104] 2f4: 09 01 40 b9 ldr w9, [x8] 2f8: a9 83 1d b8 stur w9, [x29, #-40] 2fc: a8 63 01 d1 sub x8, x29, #88 300: 08 61 00 91 add x8, x8, #24 304: a9 03 5c b8 ldur w9, [x29, #-64] 308: ea 03 09 2a mov w10, w9 30c: 68 32 00 f9 str x8, [x19, #96] 310: 6a 5e 00 b9 str w10, [x19, #92] 314: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x31c> 318: 01 00 00 14 b #4 <nonleaf_call+0x2e8> 31c: 68 5e 40 b9 ldr w8, [x19, #92] 320: 09 21 00 11 add w9, w8, #8 324: 6a 32 40 f9 ldr x10, [x19, #96] 328: 49 01 00 b9 str w9, [x10] 32c: 29 01 00 71 subs w9, w9, #0 330: 69 5a 00 b9 str w9, [x19, #88] 334: ec 00 00 54 b.gt #28 <nonleaf_call+0x31c> 338: 01 00 00 14 b #4 <nonleaf_call+0x308> 33c: a8 03 5b f8 ldur x8, [x29, #-80] 340: 69 5e 40 b9 ldr w9, [x19, #92] 344: 08 c1 29 8b add x8, x8, w9, sxtw 348: 68 2a 00 f9 str x8, [x19, #80] 34c: 06 00 00 14 b #24 <nonleaf_call+0x330> 350: a8 83 5a f8 ldur x8, [x29, #-88] 354: 09 21 00 91 add x9, x8, #8 358: a9 83 1a f8 stur x9, [x29, #-88] 35c: 68 2a 00 f9 str x8, [x19, #80] 360: 01 00 00 14 b #4 <nonleaf_call+0x330> 364: 68 2a 40 f9 ldr x8, [x19, #80] 368: 09 01 40 b9 ldr w9, [x8] 36c: a9 43 1d b8 stur w9, [x29, #-44] 370: a8 63 01 d1 sub x8, x29, #88 374: 08 61 00 91 add x8, x8, #24 378: a9 03 5c b8 ldur w9, [x29, #-64] 37c: ea 03 09 2a mov w10, w9 380: 68 26 00 f9 str x8, [x19, #72] 384: 6a 46 00 b9 str w10, [x19, #68] 388: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x390> 38c: 01 00 00 14 b #4 <nonleaf_call+0x35c> 390: 68 46 40 b9 ldr w8, [x19, #68] 394: 09 21 00 11 add w9, w8, #8 398: 6a 26 40 f9 ldr x10, [x19, #72] 39c: 49 01 00 b9 str w9, [x10] 3a0: 29 01 00 71 subs w9, w9, #0 3a4: 69 42 00 b9 str w9, [x19, #64] 3a8: ec 00 00 54 b.gt #28 <nonleaf_call+0x390> 3ac: 01 00 00 14 b #4 <nonleaf_call+0x37c> 3b0: a8 03 5b f8 ldur x8, [x29, #-80] 3b4: 69 46 40 b9 ldr w9, [x19, #68] 3b8: 08 c1 29 8b add x8, x8, w9, sxtw 3bc: 68 1e 00 f9 str x8, [x19, #56] 3c0: 06 00 00 14 b #24 <nonleaf_call+0x3a4> 3c4: a8 83 5a f8 ldur x8, [x29, #-88] 3c8: 09 21 00 91 add x9, x8, #8 3cc: a9 83 1a f8 stur x9, [x29, #-88] 3d0: 68 1e 00 f9 str x8, [x19, #56] 3d4: 01 00 00 14 b #4 <nonleaf_call+0x3a4> 3d8: 68 1e 40 f9 ldr x8, [x19, #56] 3dc: 09 01 40 b9 ldr w9, [x8] 3e0: a9 03 1d b8 stur w9, [x29, #-48] 3e4: a8 63 01 d1 sub x8, x29, #88 3e8: 08 61 00 91 add x8, x8, #24 3ec: a9 03 5c b8 ldur w9, [x29, #-64] 3f0: ea 03 09 2a mov w10, w9 3f4: 68 1a 00 f9 str x8, [x19, #48] 3f8: 6a 2e 00 b9 str w10, [x19, #44] 3fc: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x404> 400: 01 00 00 14 b #4 <nonleaf_call+0x3d0> 404: 68 2e 40 b9 ldr w8, [x19, #44] 408: 09 21 00 11 add w9, w8, #8 40c: 6a 1a 40 f9 ldr x10, [x19, #48] 410: 49 01 00 b9 str w9, [x10] 414: 29 01 00 71 subs w9, w9, #0 418: 69 2a 00 b9 str w9, [x19, #40] 41c: ec 00 00 54 b.gt #28 <nonleaf_call+0x404> 420: 01 00 00 14 b #4 <nonleaf_call+0x3f0> 424: a8 03 5b f8 ldur x8, [x29, #-80] 428: 69 2e 40 b9 ldr w9, [x19, #44] 42c: 08 c1 29 8b add x8, x8, w9, sxtw 430: 68 12 00 f9 str x8, [x19, #32] 434: 06 00 00 14 b #24 <nonleaf_call+0x418> 438: a8 83 5a f8 ldur x8, [x29, #-88] 43c: 09 21 00 91 add x9, x8, #8 440: a9 83 1a f8 stur x9, [x29, #-88] 444: 68 12 00 f9 str x8, [x19, #32] 448: 01 00 00 14 b #4 <nonleaf_call+0x418> 44c: 68 12 40 f9 ldr x8, [x19, #32] 450: 09 01 40 b9 ldr w9, [x8] 454: a9 c3 1c b8 stur w9, [x29, #-52] 458: a8 63 01 d1 sub x8, x29, #88 45c: 08 61 00 91 add x8, x8, #24 460: a9 03 5c b8 ldur w9, [x29, #-64] 464: ea 03 09 2a mov w10, w9 468: 68 0e 00 f9 str x8, [x19, #24] 46c: 6a 16 00 b9 str w10, [x19, #20] 470: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x478> 474: 01 00 00 14 b #4 <nonleaf_call+0x444> 478: 68 16 40 b9 ldr w8, [x19, #20] 47c: 09 21 00 11 add w9, w8, #8 480: 6a 0e 40 f9 ldr x10, [x19, #24] 484: 49 01 00 b9 str w9, [x10] 488: 29 01 00 71 subs w9, w9, #0 48c: 69 12 00 b9 str w9, [x19, #16] 490: ec 00 00 54 b.gt #28 <nonleaf_call+0x478> 494: 01 00 00 14 b #4 <nonleaf_call+0x464> 498: a8 03 5b f8 ldur x8, [x29, #-80] 49c: 69 16 40 b9 ldr w9, [x19, #20] 4a0: 08 c1 29 8b add x8, x8, w9, sxtw 4a4: 68 06 00 f9 str x8, [x19, #8] 4a8: 06 00 00 14 b #24 <nonleaf_call+0x48c> 4ac: a8 83 5a f8 ldur x8, [x29, #-88] 4b0: 09 21 00 91 add x9, x8, #8 4b4: a9 83 1a f8 stur x9, [x29, #-88] 4b8: 68 06 00 f9 str x8, [x19, #8] 4bc: 01 00 00 14 b #4 <nonleaf_call+0x48c> 4c0: 68 06 40 f9 ldr x8, [x19, #8] 4c4: 09 01 40 b9 ldr w9, [x8] 4c8: a9 83 1c b8 stur w9, [x29, #-56] 4cc: e8 03 00 91 mov x8, sp 4d0: 0a 81 03 f1 subs x10, x8, #224 4d4: 5f 01 00 91 mov sp, x10 4d8: 89 09 80 52 mov w9, #76 4dc: 09 01 12 38 sturb w9, [x8, #-224] 4e0: a0 83 5e b8 ldur w0, [x29, #-24] 4e4: a1 43 5e b8 ldur w1, [x29, #-28] 4e8: a2 03 5e b8 ldur w2, [x29, #-32] 4ec: a3 c3 5d b8 ldur w3, [x29, #-36] 4f0: a4 83 5d b8 ldur w4, [x29, #-40] 4f4: a5 43 5d b8 ldur w5, [x29, #-44] 4f8: a6 03 5d b8 ldur w6, [x29, #-48] 4fc: a7 c3 5c b8 ldur w7, [x29, #-52] 500: a9 83 5c b8 ldur w9, [x29, #-56] 504: ff 43 00 d1 sub sp, sp, #16 508: e8 03 00 91 mov x8, sp 50c: 09 01 00 b9 str w9, [x8] 510: bc fe ff 97 bl #-1296 <leaf_call> 514: ff 43 00 91 add sp, sp, #16 518: bf 43 00 d1 sub sp, x29, #16 51c: fd 7b 41 a9 ldp x29, x30, [sp, #16] 520: fc 4f c2 a8 ldp x28, x19, [sp], #32 524: c0 03 5f d6 ret 0000000000000528 main: 528: ff c3 00 d1 sub sp, sp, #48 52c: fd 7b 02 a9 stp x29, x30, [sp, #32] 530: fd 83 00 91 add x29, sp, #32 534: 08 00 80 52 mov w8, #0 538: e1 03 00 32 orr w1, wzr, #0x1 53c: e2 03 1f 32 orr w2, wzr, #0x2 540: e3 07 00 32 orr w3, wzr, #0x3 544: e4 03 1e 32 orr w4, wzr, #0x4 548: a5 00 80 52 mov w5, #5 54c: e6 07 1f 32 orr w6, wzr, #0x6 550: e7 0b 00 32 orr w7, wzr, #0x7 554: e9 03 1d 32 orr w9, wzr, #0x8 558: 2a 01 80 52 mov w10, #9 55c: bf c3 1f b8 stur wzr, [x29, #-4] 560: e0 03 08 2a mov w0, w8 564: eb 03 00 91 mov x11, sp 568: 69 01 00 b9 str w9, [x11] 56c: eb 03 00 91 mov x11, sp 570: 6a 09 00 b9 str w10, [x11, #8] 574: a8 83 1f b8 stur w8, [x29, #-8] 578: af fe ff 97 bl #-1348 <nonleaf_call> 57c: a0 83 5f b8 ldur w0, [x29, #-8] 580: fd 7b 42 a9 ldp x29, x30, [sp, #32] 584: ff c3 00 91 add sp, sp, #48 588: c0 03 5f d6 ret ; ---------- for spilling with a float ----------> ; #include <stdlib.h> ; #include <stdarg.h> ; ; void leaf_call(int b, int c, int d, int e, float f, int g, int h, int i, int j) ; { ; } ; ; void nonleaf_call(int a, ...) ; { ; int b,c,d,e,g,h,i,j; ; float f; ; va_list ap; ; va_start(ap, a); ; b = va_arg(ap, int); ; c = va_arg(ap, int); ; d = va_arg(ap, int); ; e = va_arg(ap, int); ; f = va_arg(ap, float); ; g = va_arg(ap, int); ; h = va_arg(ap, int); ; i = va_arg(ap, int); ; j = va_arg(ap, int); ; ; /* use some local data */ ; *(char*)alloca(220) = 'L'; ; leaf_call(b, c, d, e, f, g, h, i, j); ; } ; ; int main() ; { ; nonleaf_call(0, 1, 2, 3, 4, 5.f, 6, 7, 8, 9); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff c3 00 d1 sub sp, sp, #48 4: e0 2f 00 b9 str w0, [sp, #44] 8: e1 2b 00 b9 str w1, [sp, #40] c: e2 27 00 b9 str w2, [sp, #36] 10: e3 23 00 b9 str w3, [sp, #32] 14: e0 1f 00 bd str s0, [sp, #28] 18: e4 1b 00 b9 str w4, [sp, #24] 1c: e5 17 00 b9 str w5, [sp, #20] 20: e6 13 00 b9 str w6, [sp, #16] 24: e7 0f 00 b9 str w7, [sp, #12] 28: ff c3 00 91 add sp, sp, #48 2c: c0 03 5f d6 ret 0000000000000030 nonleaf_call: 30: fc 4f be a9 stp x28, x19, [sp, #-32]! 34: fd 7b 01 a9 stp x29, x30, [sp, #16] 38: fd 43 00 91 add x29, sp, #16 3c: ff 83 07 d1 sub sp, sp, #480 40: f3 03 00 91 mov x19, sp 44: 67 56 80 3d str q7, [x19, #336] 48: 66 52 80 3d str q6, [x19, #320] 4c: 65 4e 80 3d str q5, [x19, #304] 50: 64 4a 80 3d str q4, [x19, #288] 54: 63 46 80 3d str q3, [x19, #272] 58: 62 42 80 3d str q2, [x19, #256] 5c: 61 3e 80 3d str q1, [x19, #240] 60: 60 3a 80 3d str q0, [x19, #224] 64: a7 03 1a f8 stur x7, [x29, #-96] 68: a6 83 19 f8 stur x6, [x29, #-104] 6c: a5 03 19 f8 stur x5, [x29, #-112] 70: a4 83 18 f8 stur x4, [x29, #-120] 74: a3 03 18 f8 stur x3, [x29, #-128] 78: a2 83 17 f8 stur x2, [x29, #-136] 7c: a1 03 17 f8 stur x1, [x29, #-144] 80: a0 c3 1e b8 stur w0, [x29, #-20] 84: e0 63 19 32 orr w0, wzr, #0xffffff80 88: a0 43 1c b8 stur w0, [x29, #-60] 8c: e0 06 80 12 mov w0, #-56 90: a0 03 1c b8 stur w0, [x29, #-64] 94: 61 82 03 91 add x1, x19, #224 98: 21 00 02 91 add x1, x1, #128 9c: a1 83 1b f8 stur x1, [x29, #-72] a0: a1 43 02 d1 sub x1, x29, #144 a4: 21 e0 00 91 add x1, x1, #56 a8: a1 03 1b f8 stur x1, [x29, #-80] ac: a1 43 00 91 add x1, x29, #16 b0: a1 83 1a f8 stur x1, [x29, #-88] b4: a1 63 01 d1 sub x1, x29, #88 b8: 21 60 00 91 add x1, x1, #24 bc: a0 03 5c b8 ldur w0, [x29, #-64] c0: e8 03 00 2a mov w8, w0 c4: 61 6e 00 f9 str x1, [x19, #216] c8: 68 d6 00 b9 str w8, [x19, #212] cc: e0 01 f8 36 tbz w0, #31, #60 <nonleaf_call+0xd8> d0: 01 00 00 14 b #4 <nonleaf_call+0xa4> d4: 68 d6 40 b9 ldr w8, [x19, #212] d8: 09 21 00 11 add w9, w8, #8 dc: 6a 6e 40 f9 ldr x10, [x19, #216] e0: 49 01 00 b9 str w9, [x10] e4: 29 01 00 71 subs w9, w9, #0 e8: 69 d2 00 b9 str w9, [x19, #208] ec: ec 00 00 54 b.gt #28 <nonleaf_call+0xd8> f0: 01 00 00 14 b #4 <nonleaf_call+0xc4> f4: a8 03 5b f8 ldur x8, [x29, #-80] f8: 69 d6 40 b9 ldr w9, [x19, #212] fc: 08 c1 29 8b add x8, x8, w9, sxtw 100: 68 66 00 f9 str x8, [x19, #200] 104: 06 00 00 14 b #24 <nonleaf_call+0xec> 108: a8 83 5a f8 ldur x8, [x29, #-88] 10c: 09 21 00 91 add x9, x8, #8 110: a9 83 1a f8 stur x9, [x29, #-88] 114: 68 66 00 f9 str x8, [x19, #200] 118: 01 00 00 14 b #4 <nonleaf_call+0xec> 11c: 68 66 40 f9 ldr x8, [x19, #200] 120: 09 01 40 b9 ldr w9, [x8] 124: a9 83 1e b8 stur w9, [x29, #-24] 128: a8 63 01 d1 sub x8, x29, #88 12c: 08 61 00 91 add x8, x8, #24 130: a9 03 5c b8 ldur w9, [x29, #-64] 134: ea 03 09 2a mov w10, w9 138: 68 62 00 f9 str x8, [x19, #192] 13c: 6a be 00 b9 str w10, [x19, #188] 140: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x14c> 144: 01 00 00 14 b #4 <nonleaf_call+0x118> 148: 68 be 40 b9 ldr w8, [x19, #188] 14c: 09 21 00 11 add w9, w8, #8 150: 6a 62 40 f9 ldr x10, [x19, #192] 154: 49 01 00 b9 str w9, [x10] 158: 29 01 00 71 subs w9, w9, #0 15c: 69 ba 00 b9 str w9, [x19, #184] 160: ec 00 00 54 b.gt #28 <nonleaf_call+0x14c> 164: 01 00 00 14 b #4 <nonleaf_call+0x138> 168: a8 03 5b f8 ldur x8, [x29, #-80] 16c: 69 be 40 b9 ldr w9, [x19, #188] 170: 08 c1 29 8b add x8, x8, w9, sxtw 174: 68 5a 00 f9 str x8, [x19, #176] 178: 06 00 00 14 b #24 <nonleaf_call+0x160> 17c: a8 83 5a f8 ldur x8, [x29, #-88] 180: 09 21 00 91 add x9, x8, #8 184: a9 83 1a f8 stur x9, [x29, #-88] 188: 68 5a 00 f9 str x8, [x19, #176] 18c: 01 00 00 14 b #4 <nonleaf_call+0x160> 190: 68 5a 40 f9 ldr x8, [x19, #176] 194: 09 01 40 b9 ldr w9, [x8] 198: a9 43 1e b8 stur w9, [x29, #-28] 19c: a8 63 01 d1 sub x8, x29, #88 1a0: 08 61 00 91 add x8, x8, #24 1a4: a9 03 5c b8 ldur w9, [x29, #-64] 1a8: ea 03 09 2a mov w10, w9 1ac: 68 56 00 f9 str x8, [x19, #168] 1b0: 6a a6 00 b9 str w10, [x19, #164] 1b4: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x1c0> 1b8: 01 00 00 14 b #4 <nonleaf_call+0x18c> 1bc: 68 a6 40 b9 ldr w8, [x19, #164] 1c0: 09 21 00 11 add w9, w8, #8 1c4: 6a 56 40 f9 ldr x10, [x19, #168] 1c8: 49 01 00 b9 str w9, [x10] 1cc: 29 01 00 71 subs w9, w9, #0 1d0: 69 a2 00 b9 str w9, [x19, #160] 1d4: ec 00 00 54 b.gt #28 <nonleaf_call+0x1c0> 1d8: 01 00 00 14 b #4 <nonleaf_call+0x1ac> 1dc: a8 03 5b f8 ldur x8, [x29, #-80] 1e0: 69 a6 40 b9 ldr w9, [x19, #164] 1e4: 08 c1 29 8b add x8, x8, w9, sxtw 1e8: 68 4e 00 f9 str x8, [x19, #152] 1ec: 06 00 00 14 b #24 <nonleaf_call+0x1d4> 1f0: a8 83 5a f8 ldur x8, [x29, #-88] 1f4: 09 21 00 91 add x9, x8, #8 1f8: a9 83 1a f8 stur x9, [x29, #-88] 1fc: 68 4e 00 f9 str x8, [x19, #152] 200: 01 00 00 14 b #4 <nonleaf_call+0x1d4> 204: 68 4e 40 f9 ldr x8, [x19, #152] 208: 09 01 40 b9 ldr w9, [x8] 20c: a9 03 1e b8 stur w9, [x29, #-32] 210: a8 63 01 d1 sub x8, x29, #88 214: 08 61 00 91 add x8, x8, #24 218: a9 03 5c b8 ldur w9, [x29, #-64] 21c: ea 03 09 2a mov w10, w9 220: 68 4a 00 f9 str x8, [x19, #144] 224: 6a 8e 00 b9 str w10, [x19, #140] 228: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x234> 22c: 01 00 00 14 b #4 <nonleaf_call+0x200> 230: 68 8e 40 b9 ldr w8, [x19, #140] 234: 09 21 00 11 add w9, w8, #8 238: 6a 4a 40 f9 ldr x10, [x19, #144] 23c: 49 01 00 b9 str w9, [x10] 240: 29 01 00 71 subs w9, w9, #0 244: 69 8a 00 b9 str w9, [x19, #136] 248: ec 00 00 54 b.gt #28 <nonleaf_call+0x234> 24c: 01 00 00 14 b #4 <nonleaf_call+0x220> 250: a8 03 5b f8 ldur x8, [x29, #-80] 254: 69 8e 40 b9 ldr w9, [x19, #140] 258: 08 c1 29 8b add x8, x8, w9, sxtw 25c: 68 42 00 f9 str x8, [x19, #128] 260: 06 00 00 14 b #24 <nonleaf_call+0x248> 264: a8 83 5a f8 ldur x8, [x29, #-88] 268: 09 21 00 91 add x9, x8, #8 26c: a9 83 1a f8 stur x9, [x29, #-88] 270: 68 42 00 f9 str x8, [x19, #128] 274: 01 00 00 14 b #4 <nonleaf_call+0x248> 278: 68 42 40 f9 ldr x8, [x19, #128] 27c: 09 01 40 b9 ldr w9, [x8] 280: a9 c3 1d b8 stur w9, [x29, #-36] 284: a8 63 01 d1 sub x8, x29, #88 288: 08 71 00 91 add x8, x8, #28 28c: a9 43 5c b8 ldur w9, [x29, #-60] 290: ea 03 09 2a mov w10, w9 294: 68 3e 00 f9 str x8, [x19, #120] 298: 6a 76 00 b9 str w10, [x19, #116] 29c: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x2a8> 2a0: 01 00 00 14 b #4 <nonleaf_call+0x274> 2a4: 68 76 40 b9 ldr w8, [x19, #116] 2a8: 09 41 00 11 add w9, w8, #16 2ac: 6a 3e 40 f9 ldr x10, [x19, #120] 2b0: 49 01 00 b9 str w9, [x10] 2b4: 29 01 00 71 subs w9, w9, #0 2b8: 69 72 00 b9 str w9, [x19, #112] 2bc: ec 00 00 54 b.gt #28 <nonleaf_call+0x2a8> 2c0: 01 00 00 14 b #4 <nonleaf_call+0x294> 2c4: a8 83 5b f8 ldur x8, [x29, #-72] 2c8: 69 76 40 b9 ldr w9, [x19, #116] 2cc: 08 c1 29 8b add x8, x8, w9, sxtw 2d0: 68 36 00 f9 str x8, [x19, #104] 2d4: 06 00 00 14 b #24 <nonleaf_call+0x2bc> 2d8: a8 83 5a f8 ldur x8, [x29, #-88] 2dc: 09 21 00 91 add x9, x8, #8 2e0: a9 83 1a f8 stur x9, [x29, #-88] 2e4: 68 36 00 f9 str x8, [x19, #104] 2e8: 01 00 00 14 b #4 <nonleaf_call+0x2bc> 2ec: 68 36 40 f9 ldr x8, [x19, #104] 2f0: 00 01 40 bd ldr s0, [x8] 2f4: a0 83 1c bc stur s0, [x29, #-56] 2f8: a8 63 01 d1 sub x8, x29, #88 2fc: 08 61 00 91 add x8, x8, #24 300: a9 03 5c b8 ldur w9, [x29, #-64] 304: ea 03 09 2a mov w10, w9 308: 68 32 00 f9 str x8, [x19, #96] 30c: 6a 5e 00 b9 str w10, [x19, #92] 310: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x31c> 314: 01 00 00 14 b #4 <nonleaf_call+0x2e8> 318: 68 5e 40 b9 ldr w8, [x19, #92] 31c: 09 21 00 11 add w9, w8, #8 320: 6a 32 40 f9 ldr x10, [x19, #96] 324: 49 01 00 b9 str w9, [x10] 328: 29 01 00 71 subs w9, w9, #0 32c: 69 5a 00 b9 str w9, [x19, #88] 330: ec 00 00 54 b.gt #28 <nonleaf_call+0x31c> 334: 01 00 00 14 b #4 <nonleaf_call+0x308> 338: a8 03 5b f8 ldur x8, [x29, #-80] 33c: 69 5e 40 b9 ldr w9, [x19, #92] 340: 08 c1 29 8b add x8, x8, w9, sxtw 344: 68 2a 00 f9 str x8, [x19, #80] 348: 06 00 00 14 b #24 <nonleaf_call+0x330> 34c: a8 83 5a f8 ldur x8, [x29, #-88] 350: 09 21 00 91 add x9, x8, #8 354: a9 83 1a f8 stur x9, [x29, #-88] 358: 68 2a 00 f9 str x8, [x19, #80] 35c: 01 00 00 14 b #4 <nonleaf_call+0x330> 360: 68 2a 40 f9 ldr x8, [x19, #80] 364: 09 01 40 b9 ldr w9, [x8] 368: a9 83 1d b8 stur w9, [x29, #-40] 36c: a8 63 01 d1 sub x8, x29, #88 370: 08 61 00 91 add x8, x8, #24 374: a9 03 5c b8 ldur w9, [x29, #-64] 378: ea 03 09 2a mov w10, w9 37c: 68 26 00 f9 str x8, [x19, #72] 380: 6a 46 00 b9 str w10, [x19, #68] 384: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x390> 388: 01 00 00 14 b #4 <nonleaf_call+0x35c> 38c: 68 46 40 b9 ldr w8, [x19, #68] 390: 09 21 00 11 add w9, w8, #8 394: 6a 26 40 f9 ldr x10, [x19, #72] 398: 49 01 00 b9 str w9, [x10] 39c: 29 01 00 71 subs w9, w9, #0 3a0: 69 42 00 b9 str w9, [x19, #64] 3a4: ec 00 00 54 b.gt #28 <nonleaf_call+0x390> 3a8: 01 00 00 14 b #4 <nonleaf_call+0x37c> 3ac: a8 03 5b f8 ldur x8, [x29, #-80] 3b0: 69 46 40 b9 ldr w9, [x19, #68] 3b4: 08 c1 29 8b add x8, x8, w9, sxtw 3b8: 68 1e 00 f9 str x8, [x19, #56] 3bc: 06 00 00 14 b #24 <nonleaf_call+0x3a4> 3c0: a8 83 5a f8 ldur x8, [x29, #-88] 3c4: 09 21 00 91 add x9, x8, #8 3c8: a9 83 1a f8 stur x9, [x29, #-88] 3cc: 68 1e 00 f9 str x8, [x19, #56] 3d0: 01 00 00 14 b #4 <nonleaf_call+0x3a4> 3d4: 68 1e 40 f9 ldr x8, [x19, #56] 3d8: 09 01 40 b9 ldr w9, [x8] 3dc: a9 43 1d b8 stur w9, [x29, #-44] 3e0: a8 63 01 d1 sub x8, x29, #88 3e4: 08 61 00 91 add x8, x8, #24 3e8: a9 03 5c b8 ldur w9, [x29, #-64] 3ec: ea 03 09 2a mov w10, w9 3f0: 68 1a 00 f9 str x8, [x19, #48] 3f4: 6a 2e 00 b9 str w10, [x19, #44] 3f8: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x404> 3fc: 01 00 00 14 b #4 <nonleaf_call+0x3d0> 400: 68 2e 40 b9 ldr w8, [x19, #44] 404: 09 21 00 11 add w9, w8, #8 408: 6a 1a 40 f9 ldr x10, [x19, #48] 40c: 49 01 00 b9 str w9, [x10] 410: 29 01 00 71 subs w9, w9, #0 414: 69 2a 00 b9 str w9, [x19, #40] 418: ec 00 00 54 b.gt #28 <nonleaf_call+0x404> 41c: 01 00 00 14 b #4 <nonleaf_call+0x3f0> 420: a8 03 5b f8 ldur x8, [x29, #-80] 424: 69 2e 40 b9 ldr w9, [x19, #44] 428: 08 c1 29 8b add x8, x8, w9, sxtw 42c: 68 12 00 f9 str x8, [x19, #32] 430: 06 00 00 14 b #24 <nonleaf_call+0x418> 434: a8 83 5a f8 ldur x8, [x29, #-88] 438: 09 21 00 91 add x9, x8, #8 43c: a9 83 1a f8 stur x9, [x29, #-88] 440: 68 12 00 f9 str x8, [x19, #32] 444: 01 00 00 14 b #4 <nonleaf_call+0x418> 448: 68 12 40 f9 ldr x8, [x19, #32] 44c: 09 01 40 b9 ldr w9, [x8] 450: a9 03 1d b8 stur w9, [x29, #-48] 454: a8 63 01 d1 sub x8, x29, #88 458: 08 61 00 91 add x8, x8, #24 45c: a9 03 5c b8 ldur w9, [x29, #-64] 460: ea 03 09 2a mov w10, w9 464: 68 0e 00 f9 str x8, [x19, #24] 468: 6a 16 00 b9 str w10, [x19, #20] 46c: e9 01 f8 36 tbz w9, #31, #60 <nonleaf_call+0x478> 470: 01 00 00 14 b #4 <nonleaf_call+0x444> 474: 68 16 40 b9 ldr w8, [x19, #20] 478: 09 21 00 11 add w9, w8, #8 47c: 6a 0e 40 f9 ldr x10, [x19, #24] 480: 49 01 00 b9 str w9, [x10] 484: 29 01 00 71 subs w9, w9, #0 488: 69 12 00 b9 str w9, [x19, #16] 48c: ec 00 00 54 b.gt #28 <nonleaf_call+0x478> 490: 01 00 00 14 b #4 <nonleaf_call+0x464> 494: a8 03 5b f8 ldur x8, [x29, #-80] 498: 69 16 40 b9 ldr w9, [x19, #20] 49c: 08 c1 29 8b add x8, x8, w9, sxtw 4a0: 68 06 00 f9 str x8, [x19, #8] 4a4: 06 00 00 14 b #24 <nonleaf_call+0x48c> 4a8: a8 83 5a f8 ldur x8, [x29, #-88] 4ac: 09 21 00 91 add x9, x8, #8 4b0: a9 83 1a f8 stur x9, [x29, #-88] 4b4: 68 06 00 f9 str x8, [x19, #8] 4b8: 01 00 00 14 b #4 <nonleaf_call+0x48c> 4bc: 68 06 40 f9 ldr x8, [x19, #8] 4c0: 09 01 40 b9 ldr w9, [x8] 4c4: a9 c3 1c b8 stur w9, [x29, #-52] 4c8: e8 03 00 91 mov x8, sp 4cc: 0a 81 03 f1 subs x10, x8, #224 4d0: 5f 01 00 91 mov sp, x10 4d4: 89 09 80 52 mov w9, #76 4d8: 09 01 12 38 sturb w9, [x8, #-224] 4dc: a0 83 5e b8 ldur w0, [x29, #-24] 4e0: a1 43 5e b8 ldur w1, [x29, #-28] 4e4: a2 03 5e b8 ldur w2, [x29, #-32] 4e8: a3 c3 5d b8 ldur w3, [x29, #-36] 4ec: a0 83 5c bc ldur s0, [x29, #-56] 4f0: a4 83 5d b8 ldur w4, [x29, #-40] 4f4: a5 43 5d b8 ldur w5, [x29, #-44] 4f8: a6 03 5d b8 ldur w6, [x29, #-48] 4fc: a7 c3 5c b8 ldur w7, [x29, #-52] 500: c0 fe ff 97 bl #-1280 <leaf_call> 504: bf 43 00 d1 sub sp, x29, #16 508: fd 7b 41 a9 ldp x29, x30, [sp, #16] 50c: fc 4f c2 a8 ldp x28, x19, [sp], #32 510: c0 03 5f d6 ret 0000000000000514 main: 514: ff 83 00 d1 sub sp, sp, #32 518: fd 7b 01 a9 stp x29, x30, [sp, #16] 51c: fd 43 00 91 add x29, sp, #16 520: 08 00 80 52 mov w8, #0 524: e1 03 00 32 orr w1, wzr, #0x1 528: e2 03 1f 32 orr w2, wzr, #0x2 52c: e3 07 00 32 orr w3, wzr, #0x3 530: e4 03 1e 32 orr w4, wzr, #0x4 534: 89 02 e8 d2 mov x9, #4617315517961601024 538: 20 01 67 9e fmov d0, x9 53c: e5 07 1f 32 orr w5, wzr, #0x6 540: e6 0b 00 32 orr w6, wzr, #0x7 544: e7 03 1d 32 orr w7, wzr, #0x8 548: 2a 01 80 52 mov w10, #9 54c: bf c3 1f b8 stur wzr, [x29, #-4] 550: e0 03 08 2a mov w0, w8 554: e9 03 00 91 mov x9, sp 558: 2a 01 00 b9 str w10, [x9] 55c: e8 0b 00 b9 str w8, [sp, #8] 560: b4 fe ff 97 bl #-1328 <nonleaf_call> 564: e0 0b 40 b9 ldr w0, [sp, #8] 568: fd 7b 41 a9 ldp x29, x30, [sp, #16] 56c: ff 83 00 91 add sp, sp, #32 570: c0 03 5f d6 ret ; ---------- structs by value ----------> ; ; struct A { int i, j; long long l; }; ; ; void leaf_call(int b, int c, int d, int e, struct A f, int g, int h) ; { ; } ; ; void nonleaf_call(int a, int b, int c, int d, int e, struct A f, int g, int h) ; { ; /* use some local data */ ; char l[100] ={ 'L'}; ; leaf_call(b, c, d, e, f, g, h); ; } ; ; int main() ; { ; nonleaf_call(0, 1, 2, 3, 4, (struct A){5, 6, 7ll}, 8, 9); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff c3 00 d1 sub sp, sp, #48 4: e4 13 00 f9 str x4, [sp, #32] 8: e5 17 00 f9 str x5, [sp, #40] c: e0 1f 00 b9 str w0, [sp, #28] 10: e1 1b 00 b9 str w1, [sp, #24] 14: e2 17 00 b9 str w2, [sp, #20] 18: e3 13 00 b9 str w3, [sp, #16] 1c: e6 0f 00 b9 str w6, [sp, #12] 20: e7 0b 00 b9 str w7, [sp, #8] 24: ff c3 00 91 add sp, sp, #48 28: c0 03 5f d6 ret 000000000000002c nonleaf_call: 2c: ff c3 02 d1 sub sp, sp, #176 30: fd 7b 0a a9 stp x29, x30, [sp, #160] 34: fd 83 02 91 add x29, sp, #160 38: a8 13 40 b9 ldr w8, [x29, #16] 3c: 09 00 80 52 mov w9, #0 40: 8a 0c 80 d2 mov x10, #100 44: 8b 09 80 52 mov w11, #76 48: ec 43 00 91 add x12, sp, #16 4c: a5 03 1f f8 stur x5, [x29, #-16] 50: a6 83 1f f8 stur x6, [x29, #-8] 54: a0 c3 1e b8 stur w0, [x29, #-20] 58: a1 83 1e b8 stur w1, [x29, #-24] 5c: a2 43 1e b8 stur w2, [x29, #-28] 60: a3 03 1e b8 stur w3, [x29, #-32] 64: a4 c3 1d b8 stur w4, [x29, #-36] 68: a7 83 1d b8 stur w7, [x29, #-40] 6c: a8 43 1d b8 stur w8, [x29, #-44] 70: e0 03 0c aa mov x0, x12 74: e1 03 09 2a mov w1, w9 78: e2 03 0a aa mov x2, x10 7c: eb 0f 00 b9 str w11, [sp, #12] 80: ec 03 00 f9 str x12, [sp] 84: 00 00 00 94 bl #0 <nonleaf_call+0x58> 88: e8 0f 40 b9 ldr w8, [sp, #12] 8c: ea 03 40 f9 ldr x10, [sp] 90: 48 01 00 39 strb w8, [x10] 94: a0 83 5e b8 ldur w0, [x29, #-24] 98: a1 43 5e b8 ldur w1, [x29, #-28] 9c: a2 03 5e b8 ldur w2, [x29, #-32] a0: a3 c3 5d b8 ldur w3, [x29, #-36] a4: a6 83 5d b8 ldur w6, [x29, #-40] a8: a7 43 5d b8 ldur w7, [x29, #-44] ac: ac 03 5f f8 ldur x12, [x29, #-16] b0: a5 83 5f f8 ldur x5, [x29, #-8] b4: e4 03 0c aa mov x4, x12 b8: d2 ff ff 97 bl #-184 <leaf_call> bc: fd 7b 4a a9 ldp x29, x30, [sp, #160] c0: ff c3 02 91 add sp, sp, #176 c4: c0 03 5f d6 ret 00000000000000c8 main: c8: ff 03 01 d1 sub sp, sp, #64 ; | cc: fd 7b 03 a9 stp x29, x30, [sp, #48] ; | prolog d0: fd c3 00 91 add x29, sp, #48 ; | d4: 08 00 80 52 mov w8, #0 ; prep arg 0 d8: a9 00 80 52 mov w9, #5 ; | i dc: ea 07 1f 32 orr w10, wzr, #0x6 ; | prep local struct A's data j e0: eb 0b 40 b2 orr x11, xzr, #0x7 ; | l e4: e1 03 00 32 orr w1, wzr, #0x1 ; arg 1 e8: e2 03 1f 32 orr w2, wzr, #0x2 ; arg 2 ec: e3 07 00 32 orr w3, wzr, #0x3 ; arg 3 f0: e4 03 1e 32 orr w4, wzr, #0x4 ; arg 4 f4: e7 03 1d 32 orr w7, wzr, #0x8 ; arg 6 f8: 2c 01 80 52 mov w12, #9 ; prep arg 7 fc: ed 63 00 91 add x13, sp, #24 ; used for indirection below, a bit pointless 100: bf c3 1f b8 stur wzr, [x29, #-4] ; zero 4 bytes in local area @@@ unsure why 104: a9 01 00 b9 str w9, [x13] ; | 108: ea 1f 00 b9 str w10, [sp, #28] ; | write struct A to local area 10c: eb 13 00 f9 str x11, [sp, #32] ; | 110: eb 0f 40 f9 ldr x11, [sp, #24] ; 1st dword of struct A -> x11 114: ed 13 40 f9 ldr x13, [sp, #32] ; 2nd dword of struct A -> x13 118: e0 03 08 2a mov w0, w8 ; arg 0 11c: e5 03 0b aa mov x5, x11 ; | 120: e6 03 0d aa mov x6, x13 ; / arg 5 (struct A), passed in regs as 2 dwords 124: eb 03 00 91 mov x11, sp ; \ 128: 6c 01 00 b9 str w12, [x11] ; | arg 7, pushed onto stack 12c: e8 17 00 b9 str w8, [sp, #20] ; prep return value, temp store on stack local area 130: bf ff ff 97 bl #-260 <nonleaf_call> ; return address -> r30/lr, and call 134: e0 17 40 b9 ldr w0, [sp, #20] ; return value (unsure why not just using immediate @@@) 138: fd 7b 43 a9 ldp x29, x30, [sp, #48] ; | 13c: ff 03 01 91 add sp, sp, #64 ; | epilog 140: c0 03 5f d6 ret ; | ; output from godbolt compiler explorer w/ msvc 19.14 |leaf_call| PROC |$LN3| sub sp,sp,#0x30 str w0,[sp] str w1,[sp,#4] str w2,[sp,#8] str w3,[sp,#0xC] str x4,[sp,#0x18] str x5,[sp,#0x20] str w6,[sp,#0x10] str w7,[sp,#0x14] add sp,sp,#0x30 ret ENDP ; |leaf_call| |nonleaf_call| PROC |$LN3| stp fp,lr,[sp,#-0x10]! mov fp,sp bl __security_push_cookie sub sp,sp,#0x90 str w0,[sp,#0x14] str w1,[sp,#0x10] str w2,[sp,#0xC] str w3,[sp,#8] str w4,[sp,#4] str x5,[sp,#0x18] str x6,[sp,#0x20] str w7,[sp] mov w8,#0x4C strb w8,[sp,#0x28] add x9,sp,#0x29 mov x8,#0 stp x8,x8,[x9] stp x8,x8,[x9,#0x10] stp x8,x8,[x9,#0x20] stp x8,x8,[x9,#0x30] stp x8,x8,[x9,#0x40] stp x8,x8,[x9,#0x50] strh w8,[x9,#0x60] strb w8,[x9,#0x62] ldr w7,[sp,#0xB0] ldr w6,[sp] ldr x5,[sp,#0x20] ldr x4,[sp,#0x18] ldr w3,[sp,#4] ldr w2,[sp,#8] ldr w1,[sp,#0xC] ldr w0,[sp,#0x10] bl leaf_call add sp,sp,#0x90 bl __security_pop_cookie ldp fp,lr,[sp],#0x10 ret ENDP ; |nonleaf_call| |main| PROC |$LN3| stp fp,lr,[sp,#-0x10]! ; | mov fp,sp ; | bl __security_push_cookie ; | prolog sub sp,sp,#0x20 ; / mov w8,#5 ; \ str w8,[sp,#0x10] ; | i mov w8,#6 ; | str w8,[sp,#0x14] ; | write struct A to local area j mov x8,#7 ; | str x8,[sp,#0x18] ; / l mov w8,#9 ; \ str w8,[sp] ; | arg 7, pushed onto stack mov w7,#8 ; arg 6 ldr x6,[sp,#0x18] ; | l ldr x5,[sp,#0x10] ; | arg 5 (struct A), passed in regs as 2 dwords i, j mov w4,#4 ; arg 4 mov w3,#3 ; arg 3 mov w2,#2 ; arg 2 mov w1,#1 ; arg 1 mov w0,#0 ; arg 0 bl nonleaf_call ; return address -> r30/lr, and call mov w0,#0 ; return value add sp,sp,#0x20 ; | bl __security_pop_cookie ; | epilog ldp fp,lr,[sp],#0x10 ; | ret ; | ENDP ; |main| ; ---------- structs by value, complex example (multiple structs) ----------> ; ; struct A { int i, j; float f; }; ; struct B { double d; long long l; }; ; ; void leaf_call(int b, struct A c, struct B d, int e, int f, struct A g, struct B h, int i, int j) ; { ; } ; ; void nonleaf_call(int a, int b, struct A c, struct B d, int e, int f, struct A g, struct B h, int i, int j) ; { ; /* use some local data */ ; char l[100] ={ 'L'}; ; leaf_call(b, c, d, e, f, g, h, i, j); ; } ; ; int main() ; { ; nonleaf_call(0, 1, (struct A){2, 3, 4.f}, (struct B){5., 6ll}, 7, 8, (struct A){9, 10, 11.f}, (struct B){12., 13ll}, 14, 15); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff 83 03 d1 sub sp, sp, #224 4: fe 6b 00 f9 str x30, [sp, #208] 8: e8 73 40 f9 ldr x8, [sp, #224] c: e9 77 40 f9 ldr x9, [sp, #232] 10: ea 7b 40 f9 ldr x10, [sp, #240] 14: eb 7f 40 f9 ldr x11, [sp, #248] 18: ec 03 41 b9 ldr w12, [sp, #256] 1c: ed 0b 41 b9 ldr w13, [sp, #264] 20: ee 07 7e b2 orr x14, xzr, #0xc 24: ef 13 03 91 add x15, sp, #196 28: f0 c3 02 91 add x16, sp, #176 2c: f1 53 02 91 add x17, sp, #148 30: f2 03 02 91 add x18, sp, #128 34: e1 5b 00 f9 str x1, [sp, #176] 38: e2 5f 00 f9 str x2, [sp, #184] 3c: e0 5b 00 b9 str w0, [sp, #88] 40: e0 03 0f aa mov x0, x15 44: e1 03 10 aa mov x1, x16 48: e2 03 0e aa mov x2, x14 4c: e5 57 00 b9 str w5, [sp, #84] 50: e6 53 00 b9 str w6, [sp, #80] 54: e8 27 00 f9 str x8, [sp, #72] 58: e9 23 00 f9 str x9, [sp, #64] 5c: ea 1f 00 f9 str x10, [sp, #56] 60: eb 1b 00 f9 str x11, [sp, #48] 64: ec 2f 00 b9 str w12, [sp, #44] 68: ed 2b 00 b9 str w13, [sp, #40] 6c: e3 13 00 f9 str x3, [sp, #32] 70: e4 0f 00 f9 str x4, [sp, #24] 74: ee 0b 00 f9 str x14, [sp, #16] 78: f1 07 00 f9 str x17, [sp, #8] 7c: f2 03 00 f9 str x18, [sp] 80: 00 00 00 94 bl #0 <leaf_call+0x80> 84: e8 13 40 f9 ldr x8, [sp, #32] 88: e8 53 00 f9 str x8, [sp, #160] 8c: e9 0f 40 f9 ldr x9, [sp, #24] 90: e9 57 00 f9 str x9, [sp, #168] 94: ea 27 40 f9 ldr x10, [sp, #72] 98: ea 43 00 f9 str x10, [sp, #128] 9c: eb 23 40 f9 ldr x11, [sp, #64] a0: eb 47 00 f9 str x11, [sp, #136] a4: e0 07 40 f9 ldr x0, [sp, #8] a8: e1 03 40 f9 ldr x1, [sp] ac: e2 0b 40 f9 ldr x2, [sp, #16] b0: 00 00 00 94 bl #0 <leaf_call+0xb0> b4: e8 1f 40 f9 ldr x8, [sp, #56] b8: e8 3b 00 f9 str x8, [sp, #112] bc: e9 1b 40 f9 ldr x9, [sp, #48] c0: e9 3f 00 f9 str x9, [sp, #120] c4: ec 5b 40 b9 ldr w12, [sp, #88] c8: ec 6f 00 b9 str w12, [sp, #108] cc: ed 57 40 b9 ldr w13, [sp, #84] d0: ed 6b 00 b9 str w13, [sp, #104] d4: e5 53 40 b9 ldr w5, [sp, #80] d8: e5 67 00 b9 str w5, [sp, #100] dc: e6 2f 40 b9 ldr w6, [sp, #44] e0: e6 63 00 b9 str w6, [sp, #96] e4: e7 2b 40 b9 ldr w7, [sp, #40] e8: e7 5f 00 b9 str w7, [sp, #92] ec: fe 6b 40 f9 ldr x30, [sp, #208] f0: ff 83 03 91 add sp, sp, #224 f4: c0 03 5f d6 ret 00000000000000f8 nonleaf_call: f8: fc 67 bb a9 stp x28, x25, [sp, #-80]! fc: f8 5f 01 a9 stp x24, x23, [sp, #16] 100: f6 57 02 a9 stp x22, x21, [sp, #32] 104: f4 4f 03 a9 stp x20, x19, [sp, #48] 108: fd 7b 04 a9 stp x29, x30, [sp, #64] 10c: fd 03 01 91 add x29, sp, #64 110: ff 43 08 d1 sub sp, sp, #528 114: a8 0b 40 f9 ldr x8, [x29, #16] 118: a9 0f 40 f9 ldr x9, [x29, #24] 11c: aa 13 40 f9 ldr x10, [x29, #32] 120: ab 17 40 f9 ldr x11, [x29, #40] 124: ac 33 40 b9 ldr w12, [x29, #48] 128: ad 3b 40 b9 ldr w13, [x29, #56] 12c: ee 07 7e b2 orr x14, xzr, #0xc 130: 0f 00 80 52 mov w15, #0 134: 90 0c 80 d2 mov x16, #100 138: 91 09 80 52 mov w17, #76 13c: b2 33 01 d1 sub x18, x29, #76 140: b3 83 01 d1 sub x19, x29, #96 144: b4 f3 01 d1 sub x20, x29, #124 148: b5 43 02 d1 sub x21, x29, #144 14c: f6 d3 04 91 add x22, sp, #308 150: f7 83 04 91 add x23, sp, #288 154: f8 43 04 91 add x24, sp, #272 158: a2 03 1a f8 stur x2, [x29, #-96] 15c: a3 83 1a f8 stur x3, [x29, #-88] 160: e0 0f 01 b9 str w0, [sp, #268] 164: e0 03 12 aa mov x0, x18 168: e1 0b 01 b9 str w1, [sp, #264] 16c: e1 03 13 aa mov x1, x19 170: e2 03 0e aa mov x2, x14 174: e6 07 01 b9 str w6, [sp, #260] 178: e7 03 01 b9 str w7, [sp, #256] 17c: e8 7f 00 f9 str x8, [sp, #248] 180: e9 7b 00 f9 str x9, [sp, #240] 184: ea 77 00 f9 str x10, [sp, #232] 188: eb 73 00 f9 str x11, [sp, #224] 18c: ec df 00 b9 str w12, [sp, #220] 190: ed db 00 b9 str w13, [sp, #216] 194: e4 6b 00 f9 str x4, [sp, #208] 198: e5 67 00 f9 str x5, [sp, #200] 19c: ee 63 00 f9 str x14, [sp, #192] 1a0: ef bf 00 b9 str w15, [sp, #188] 1a4: f0 5b 00 f9 str x16, [sp, #176] 1a8: f1 af 00 b9 str w17, [sp, #172] 1ac: f2 53 00 f9 str x18, [sp, #160] 1b0: f4 4f 00 f9 str x20, [sp, #152] 1b4: f5 4b 00 f9 str x21, [sp, #144] 1b8: f6 47 00 f9 str x22, [sp, #136] 1bc: f7 43 00 f9 str x23, [sp, #128] 1c0: f8 3f 00 f9 str x24, [sp, #120] 1c4: 00 00 00 94 bl #0 <nonleaf_call+0xcc> 1c8: e8 6b 40 f9 ldr x8, [sp, #208] 1cc: a8 03 19 f8 stur x8, [x29, #-112] 1d0: e9 67 40 f9 ldr x9, [sp, #200] 1d4: a9 83 19 f8 stur x9, [x29, #-104] 1d8: ea 7f 40 f9 ldr x10, [sp, #248] 1dc: aa 03 17 f8 stur x10, [x29, #-144] 1e0: eb 7b 40 f9 ldr x11, [sp, #240] 1e4: ab 83 17 f8 stur x11, [x29, #-136] 1e8: e0 4f 40 f9 ldr x0, [sp, #152] 1ec: e1 4b 40 f9 ldr x1, [sp, #144] 1f0: e2 63 40 f9 ldr x2, [sp, #192] 1f4: 00 00 00 94 bl #0 <nonleaf_call+0xfc> 1f8: e8 77 40 f9 ldr x8, [sp, #232] 1fc: a8 03 16 f8 stur x8, [x29, #-160] 200: e9 73 40 f9 ldr x9, [sp, #224] 204: a9 83 16 f8 stur x9, [x29, #-152] 208: ec 0f 41 b9 ldr w12, [sp, #268] 20c: ac c3 15 b8 stur w12, [x29, #-164] 210: ed 0b 41 b9 ldr w13, [sp, #264] 214: ad 83 15 b8 stur w13, [x29, #-168] 218: ef 07 41 b9 ldr w15, [sp, #260] 21c: af 43 15 b8 stur w15, [x29, #-172] 220: f1 03 41 b9 ldr w17, [sp, #256] 224: b1 03 15 b8 stur w17, [x29, #-176] 228: e6 df 40 b9 ldr w6, [sp, #220] 22c: a6 c3 14 b8 stur w6, [x29, #-180] 230: e7 db 40 b9 ldr w7, [sp, #216] 234: a7 83 14 b8 stur w7, [x29, #-184] 238: e0 47 40 f9 ldr x0, [sp, #136] 23c: f9 bf 40 b9 ldr w25, [sp, #188] 240: e1 03 19 2a mov w1, w25 244: e2 5b 40 f9 ldr x2, [sp, #176] 248: 00 00 00 94 bl #0 <nonleaf_call+0x150> 24c: ec af 40 b9 ldr w12, [sp, #172] 250: e8 47 40 f9 ldr x8, [sp, #136] 254: 0c 01 00 39 strb w12, [x8] 258: a0 83 55 b8 ldur w0, [x29, #-168] 25c: a5 43 55 b8 ldur w5, [x29, #-172] 260: a6 03 55 b8 ldur w6, [x29, #-176] 264: ad c3 54 b8 ldur w13, [x29, #-180] 268: af 83 54 b8 ldur w15, [x29, #-184] 26c: e9 43 40 f9 ldr x9, [sp, #128] 270: e0 77 00 b9 str w0, [sp, #116] 274: e0 03 09 aa mov x0, x9 278: e1 53 40 f9 ldr x1, [sp, #160] 27c: e2 63 40 f9 ldr x2, [sp, #192] 280: e5 73 00 b9 str w5, [sp, #112] 284: e6 6f 00 b9 str w6, [sp, #108] 288: ed 6b 00 b9 str w13, [sp, #104] 28c: ef 67 00 b9 str w15, [sp, #100] 290: 00 00 00 94 bl #0 <nonleaf_call+0x198> 294: e8 93 40 f9 ldr x8, [sp, #288] 298: e9 97 40 f9 ldr x9, [sp, #296] 29c: aa 03 59 f8 ldur x10, [x29, #-112] 2a0: ab 83 59 f8 ldur x11, [x29, #-104] 2a4: e0 3f 40 f9 ldr x0, [sp, #120] 2a8: e1 4f 40 f9 ldr x1, [sp, #152] 2ac: e2 63 40 f9 ldr x2, [sp, #192] 2b0: e8 2f 00 f9 str x8, [sp, #88] 2b4: e9 2b 00 f9 str x9, [sp, #80] 2b8: ea 27 00 f9 str x10, [sp, #72] 2bc: eb 23 00 f9 str x11, [sp, #64] 2c0: 00 00 00 94 bl #0 <nonleaf_call+0x1c8> 2c4: e8 8b 40 f9 ldr x8, [sp, #272] 2c8: e9 8f 40 f9 ldr x9, [sp, #280] 2cc: aa 03 56 f8 ldur x10, [x29, #-160] 2d0: ab 83 56 f8 ldur x11, [x29, #-152] 2d4: ee 2f 40 f9 ldr x14, [sp, #88] 2d8: f0 2b 40 f9 ldr x16, [sp, #80] 2dc: f2 27 40 f9 ldr x18, [sp, #72] 2e0: e0 23 40 f9 ldr x0, [sp, #64] 2e4: ec 77 40 b9 ldr w12, [sp, #116] 2e8: e0 1f 00 f9 str x0, [sp, #56] 2ec: e0 03 0c 2a mov w0, w12 2f0: e1 03 0e aa mov x1, x14 2f4: e2 03 10 aa mov x2, x16 2f8: e3 03 12 aa mov x3, x18 2fc: e4 1f 40 f9 ldr x4, [sp, #56] 300: e5 73 40 b9 ldr w5, [sp, #112] 304: e6 6f 40 b9 ldr w6, [sp, #108] 308: ee 03 00 91 mov x14, sp 30c: c8 01 00 f9 str x8, [x14] 310: e8 03 00 91 mov x8, sp 314: 09 05 00 f9 str x9, [x8, #8] 318: e8 03 00 91 mov x8, sp 31c: 0a 09 00 f9 str x10, [x8, #16] 320: e8 03 00 91 mov x8, sp 324: 0b 0d 00 f9 str x11, [x8, #24] 328: e8 03 00 91 mov x8, sp 32c: ed 6b 40 b9 ldr w13, [sp, #104] 330: 0d 21 00 b9 str w13, [x8, #32] 334: e8 03 00 91 mov x8, sp 338: ef 67 40 b9 ldr w15, [sp, #100] 33c: 0f 29 00 b9 str w15, [x8, #40] 340: 30 ff ff 97 bl #-832 <leaf_call> 344: ff 43 08 91 add sp, sp, #528 348: fd 7b 44 a9 ldp x29, x30, [sp, #64] 34c: f4 4f 43 a9 ldp x20, x19, [sp, #48] 350: f6 57 42 a9 ldp x22, x21, [sp, #32] 354: f8 5f 41 a9 ldp x24, x23, [sp, #16] 358: fc 67 c5 a8 ldp x28, x25, [sp], #80 35c: c0 03 5f d6 ret 0000000000000360 main: 360: ff c3 04 d1 sub sp, sp, #304 364: fc 4f 11 a9 stp x28, x19, [sp, #272] 368: fd 7b 12 a9 stp x29, x30, [sp, #288] 36c: fd 83 04 91 add x29, sp, #288 370: 08 00 80 52 mov w8, #0 374: e9 03 1f 32 orr w9, wzr, #0x2 378: ea 07 00 32 orr w10, wzr, #0x3 37c: 0b 10 a8 52 mov w11, #1082130432 380: 60 01 27 1e fmov s0, w11 384: 8c 02 e8 d2 mov x12, #4617315517961601024 388: 81 01 67 9e fmov d1, x12 38c: ec 07 7f b2 orr x12, xzr, #0x6 390: 2b 01 80 52 mov w11, #9 394: 4d 01 80 52 mov w13, #10 398: 0e 26 a8 52 mov w14, #1093664768 39c: c2 01 27 1e fmov s2, w14 3a0: 0f 05 e8 d2 mov x15, #4622945017495814144 3a4: e3 01 67 9e fmov d3, x15 3a8: af 01 80 d2 mov x15, #13 3ac: f0 07 7e b2 orr x16, xzr, #0xc 3b0: e1 03 00 32 orr w1, wzr, #0x1 3b4: e6 0b 00 32 orr w6, wzr, #0x7 3b8: e7 03 1d 32 orr w7, wzr, #0x8 3bc: ee 0b 1f 32 orr w14, wzr, #0xe 3c0: f1 0f 00 32 orr w17, wzr, #0xf 3c4: b2 83 00 d1 sub x18, x29, #32 3c8: a0 c3 00 d1 sub x0, x29, #48 3cc: a2 f3 00 d1 sub x2, x29, #60 3d0: a3 43 01 d1 sub x3, x29, #80 3d4: a4 83 01 d1 sub x4, x29, #96 3d8: a5 c3 01 d1 sub x5, x29, #112 3dc: bf c3 1e b8 stur wzr, [x29, #-20] 3e0: 49 02 00 b9 str w9, [x18] 3e4: aa 43 1e b8 stur w10, [x29, #-28] 3e8: a0 83 1e bc stur s0, [x29, #-24] 3ec: 01 00 00 fd str d1, [x0] 3f0: ac 83 1d f8 stur x12, [x29, #-40] 3f4: 4b 00 00 b9 str w11, [x2] 3f8: ad 83 1c b8 stur w13, [x29, #-56] 3fc: a2 c3 1c bc stur s2, [x29, #-52] 400: 63 00 00 fd str d3, [x3] 404: af 83 1b f8 stur x15, [x29, #-72] 408: e0 03 04 aa mov x0, x4 40c: a1 c3 18 b8 stur w1, [x29, #-116] 410: e1 03 12 aa mov x1, x18 414: a2 03 18 f8 stur x2, [x29, #-128] 418: e2 03 10 aa mov x2, x16 41c: a8 c3 17 b8 stur w8, [x29, #-132] 420: f0 4b 00 f9 str x16, [sp, #144] 424: e6 8f 00 b9 str w6, [sp, #140] 428: e7 8b 00 b9 str w7, [sp, #136] 42c: ee 87 00 b9 str w14, [sp, #132] 430: f1 83 00 b9 str w17, [sp, #128] 434: e5 3f 00 f9 str x5, [sp, #120] 438: 00 00 00 94 bl #0 <main+0xd8> 43c: ac 03 5a f8 ldur x12, [x29, #-96] 440: af 83 5a f8 ldur x15, [x29, #-88] 444: b0 03 5d f8 ldur x16, [x29, #-48] 448: b2 83 5d f8 ldur x18, [x29, #-40] 44c: e0 3f 40 f9 ldr x0, [sp, #120] 450: a1 03 58 f8 ldur x1, [x29, #-128] 454: e2 4b 40 f9 ldr x2, [sp, #144] 458: ec 3b 00 f9 str x12, [sp, #112] 45c: ef 37 00 f9 str x15, [sp, #104] 460: f0 33 00 f9 str x16, [sp, #96] 464: f2 2f 00 f9 str x18, [sp, #88] 468: 00 00 00 94 bl #0 <main+0x108> 46c: ac 03 59 f8 ldur x12, [x29, #-112] 470: af 83 59 f8 ldur x15, [x29, #-104] 474: b0 03 5b f8 ldur x16, [x29, #-80] 478: b2 83 5b f8 ldur x18, [x29, #-72] 47c: e0 3b 40 f9 ldr x0, [sp, #112] 480: e1 37 40 f9 ldr x1, [sp, #104] 484: e2 33 40 f9 ldr x2, [sp, #96] 488: e3 2f 40 f9 ldr x3, [sp, #88] 48c: a8 c3 57 b8 ldur w8, [x29, #-132] 490: e0 2b 00 f9 str x0, [sp, #80] 494: e0 03 08 2a mov w0, w8 498: a9 c3 58 b8 ldur w9, [x29, #-116] 49c: e1 27 00 f9 str x1, [sp, #72] 4a0: e1 03 09 2a mov w1, w9 4a4: e4 2b 40 f9 ldr x4, [sp, #80] 4a8: e2 23 00 f9 str x2, [sp, #64] 4ac: e2 03 04 aa mov x2, x4 4b0: e5 27 40 f9 ldr x5, [sp, #72] 4b4: e3 1f 00 f9 str x3, [sp, #56] 4b8: e3 03 05 aa mov x3, x5 4bc: e4 23 40 f9 ldr x4, [sp, #64] 4c0: e5 1f 40 f9 ldr x5, [sp, #56] 4c4: e6 8f 40 b9 ldr w6, [sp, #140] 4c8: e7 8b 40 b9 ldr w7, [sp, #136] 4cc: f3 03 00 91 mov x19, sp 4d0: 6c 02 00 f9 str x12, [x19] 4d4: ec 03 00 91 mov x12, sp 4d8: 8f 05 00 f9 str x15, [x12, #8] 4dc: ec 03 00 91 mov x12, sp 4e0: 90 09 00 f9 str x16, [x12, #16] 4e4: ec 03 00 91 mov x12, sp 4e8: 92 0d 00 f9 str x18, [x12, #24] 4ec: ec 03 00 91 mov x12, sp 4f0: ea 87 40 b9 ldr w10, [sp, #132] 4f4: 8a 21 00 b9 str w10, [x12, #32] 4f8: ec 03 00 91 mov x12, sp 4fc: eb 83 40 b9 ldr w11, [sp, #128] 500: 8b 29 00 b9 str w11, [x12, #40] 504: fd fe ff 97 bl #-1036 <nonleaf_call> 508: a0 c3 57 b8 ldur w0, [x29, #-132] 50c: fd 7b 52 a9 ldp x29, x30, [sp, #288] 510: fc 4f 51 a9 ldp x28, x19, [sp, #272] 514: ff c3 04 91 add sp, sp, #304 518: c0 03 5f d6 ret ; ---------- returning long long ----------> ; ; long long f() ; { ; return 7171LL; ; } ; ; int main() ; { ; return (int)f(); ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 f: 0: 60 80 83 d2 mov x0, #7171 4: c0 03 5f d6 ret 0000000000000008 main: 8: ff 83 00 d1 sub sp, sp, #32 c: fd 7b 01 a9 stp x29, x30, [sp, #16] 10: fd 43 00 91 add x29, sp, #16 14: bf c3 1f b8 stur wzr, [x29, #-4] 18: fa ff ff 97 bl #-24 <f> 1c: e8 03 00 2a mov w8, w0 20: e0 03 08 2a mov w0, w8 24: fd 7b 41 a9 ldp x29, x30, [sp, #16] 28: ff 83 00 91 add sp, sp, #32 2c: c0 03 5f d6 ret ; ---------- passing structs with only fp parts ----------> ; ; struct A { float a; }; ; struct B { float a, b; }; ; struct C { float a, b, c; }; ; struct D { double a; }; ; struct E { double a, b; }; ; struct F { double a, b, c; }; ; ; void leaf_call(struct A a, struct B b, struct C c, struct D d, struct E e, struct F f) ; { ; } ; ; int main() ; { ; leaf_call((struct A){1.f}, (struct B){2.f,3.f}, (struct C){4.f,5.f,6.f}, (struct D){1.}, (struct E){2.,3.}, (struct F){4.,5.,6.}); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff 43 01 d1 sub sp, sp, #80 4: e7 33 40 fd ldr d7, [sp, #96] 8: f0 37 40 fd ldr d16, [sp, #104] c: f1 3b 40 fd ldr d17, [sp, #112] 10: f2 2b 40 fd ldr d18, [sp, #80] 14: f3 2f 40 fd ldr d19, [sp, #88] 18: e0 4b 00 bd str s0, [sp, #72] 1c: e2 47 00 bd str s2, [sp, #68] 20: e1 43 00 bd str s1, [sp, #64] 24: e5 3b 00 bd str s5, [sp, #56] 28: e4 37 00 bd str s4, [sp, #52] 2c: e3 33 00 bd str s3, [sp, #48] 30: e6 17 00 fd str d6, [sp, #40] 34: f3 13 00 fd str d19, [sp, #32] 38: f2 0f 00 fd str d18, [sp, #24] 3c: f1 0b 00 fd str d17, [sp, #16] 40: f0 07 00 fd str d16, [sp, #8] 44: e7 03 00 fd str d7, [sp] 48: ff 43 01 91 add sp, sp, #80 4c: c0 03 5f d6 ret 0000000000000050 main: 50: ff 43 02 d1 sub sp, sp, #144 ; | 54: fd 7b 08 a9 stp x29, x30, [sp, #128] ; | prolog 58: fd 03 02 91 add x29, sp, #128 ; / 5c: e8 03 1f 2a mov w8, wzr ; \ | | 60: a8 c3 1f b8 stur w8, [x29, #-4] ; | | | zero 4 bytes in local area @@@ struct padding? 64: e9 1b 09 32 orr w9, wzr, #0x3f800000 ; | struct A 1.f | 68: a9 83 1f b8 stur w9, [x29, #-8] ; / | 6c: e9 03 02 32 orr w9, wzr, #0x40000000 ; \ 2.f | 70: a9 03 1f b8 stur w9, [x29, #-16] ; | | 74: 09 08 a8 52 mov w9, #1077936128 ; | struct B 3.f | 78: a9 43 1f b8 stur w9, [x29, #-12] ; / | 7c: 09 10 a8 52 mov w9, #1082130432 ; \ 4.f | 80: a9 03 1e b8 stur w9, [x29, #-32] ; | | 84: 09 14 a8 52 mov w9, #1084227584 ; | 5.f | 88: a9 43 1e b8 stur w9, [x29, #-28] ; | struct C | write local struct data 8c: 09 18 a8 52 mov w9, #1086324736 ; | 6.f | 90: a9 83 1e b8 stur w9, [x29, #-24] ; / | 94: ea 27 4c b2 orr x10, xzr, #0x3ff0000000000000 ; \ 1.0 | 98: aa 83 1d f8 stur x10, [x29, #-40] ; / struct D | 9c: ea 03 42 b2 orr x10, xzr, #0x4000000000000000 ; \ 2.0 | a0: aa 83 1c f8 stur x10, [x29, #-56] ; | | a4: 0a 01 e8 d2 mov x10, #4613937818241073152 ; | struct E 3.0 | a8: aa 03 1d f8 stur x10, [x29, #-48] ; / | ac: 0a 02 e8 d2 mov x10, #4616189618054758400 ; \ 4.0 | b0: ea 1b 00 f9 str x10, [sp, #48] ; | | b4: 8a 02 e8 d2 mov x10, #4617315517961601024 ; | struct F 5.0 | b8: ea 1f 00 f9 str x10, [sp, #56] ; | | bc: 0a 03 e8 d2 mov x10, #4618441417868443648 ; | 6.0 | c0: ea 23 00 f9 str x10, [sp, #64] ; / | c4: a0 83 5f bc ldur s0, [x29, #-8] ; arg 0 (struct A), via reg c8: a2 43 5f bc ldur s2, [x29, #-12] ; | cc: a1 03 5f bc ldur s1, [x29, #-16] ; / arg 1 (struct B), via reg d0: a5 83 5e bc ldur s5, [x29, #-24] ; \ d4: a4 43 5e bc ldur s4, [x29, #-28] ; | arg 2 (struct C), via reg d8: a3 03 5e bc ldur s3, [x29, #-32] ; / dc: a6 83 5d fc ldur d6, [x29, #-40] ; arg 3 (struct D) e0: a7 83 5c fc ldur d7, [x29, #-56] ; | e4: b0 03 5d fc ldur d16, [x29, #-48] ; / prep arg 4 (struct E), note d7 is *not* used to pass, but just a scratch reg e8: f1 1b 40 fd ldr d17, [sp, #48] ; \ ec: f2 1f 40 fd ldr d18, [sp, #56] ; | prep arg 5 (struct F) f0: f3 23 40 fd ldr d19, [sp, #64] ; / f4: ea 03 00 91 mov x10, sp ; sp in x10, for below indirections (a bit pointless) f8: 53 11 00 fd str d19, [x10, #32] ; \ fc: 52 0d 00 fd str d18, [x10, #24] ; | arg 5 (struct F), via stack 100: 51 09 00 fd str d17, [x10, #16] ; / 104: 50 05 00 fd str d16, [x10, #8] ; \ arg 4 (struct E), via stack (not split across regs and stack) 108: 47 01 00 fd str d7, [x10] ; | 10c: e8 2f 00 b9 str w8, [sp, #44] ; prep return value, temp store on stack local area 110: bc ff ff 97 bl #-272 <leaf_call> ; return address -> r30/lr, and call 114: e0 2f 40 b9 ldr w0, [sp, #44] ; return value (unsure why not just using immediate @@@) 118: fd 7b 48 a9 ldp x29, x30, [sp, #128] ; | 11c: ff 43 02 91 add sp, sp, #144 ; | epilog 120: c0 03 5f d6 ret ; | ; output from godbolt compiler explorer w/ msvc 19.14 |leaf_call| PROC |$LN3| sub sp,sp,#0x30 str s0,[sp] str s1,[sp,#8] str s2,[sp,#0xC] str s3,[sp,#0x18] str s4,[sp,#0x1C] str s5,[sp,#0x20] str d6,[sp,#0x10] add sp,sp,#0x30 ret ENDP ; |leaf_call| |main| PROC |$LN3| stp fp,lr,[sp,#-0x60]! ; | mov fp,sp ; | prolog sub sp,sp,#0x30 ; / fmov s16,#1 ; \ struct A 1.f | str s16,[sp,#0x40] ; / | fmov s16,#2 ; \ 2.f | str s16,[sp,#0x48] ; | | fmov s16,#3 ; | struct B 3.f | str s16,[sp,#0x4C] ; / | fmov s16,#4 ; \ 4.f | str s16,[sp,#0x58] ; | | fmov s16,#5 ; | 5.f | str s16,[sp,#0x5C] ; | struct C | fmov s16,#6 ; | 6.f | str s16,[sp,#0x60] ; / | write local struct data fmov d16,#1 ; \ 1.0 | str d16,[sp,#0x50] ; / struct D | fmov d16,#2 ; \ 2.0 | str d16,[sp,#0x68] ; | | fmov d16,#3 ; | struct E 3.0 | str d16,[sp,#0x70] ; / | fmov d16,#4 ; \ 4.0 | str d16,[sp,#0x78] ; | | fmov d16,#5 ; | struct F 5.0 | str d16,[sp,#0x80] ; | | fmov d16,#6 ; | 6.0 | str d16,[sp,#0x88] ; / | mov x10,sp ; write ptr (top of stack) add x8,sp,#0x68 ; read ptr (beg of struct E) ldp x9,x8,[x8] ; \ stp x9,x8,[x10] ; / arg 4 (struct E), via stack (not split across regs and stack) add x11,sp,#0x10 ; write ptr (top of stack + 16) add x10,sp,#0x78 ; read ptr (beg of struct F) ldp x9,x8,[x10] ; \ stp x9,x8,[x11] ; | arg 5 (struct F), via stack ldr x8,[x10,#0x10] ; | str x8,[x11,#0x10] ; / ldr d6,[sp,#0x50] ; arg 3 (struct D), via reg ldr s5,[sp,#0x60] ; \ ldr s4,[sp,#0x5C] ; | arg 2 (struct C), via reg ldr s3,[sp,#0x58] ; / ldr s2,[sp,#0x4C] ; \ ldr s1,[sp,#0x48] ; / arg 1 (struct B), via reg ldr s0,[sp,#0x40] ; arg 0 (struct A), via reg bl leaf_call ; return address -> r30/lr, and call mov w0,#0 ; return value add sp,sp,#0x30 ; | ldp fp,lr,[sp],#0x60 ; | epilog ret ; | ENDP ; |main| ; ---------- returning structs by value ----------> ; ; struct Small { char x; }; ; struct Big { long long i,j,k,l; long m; }; /* bigger than 16b */ ; ; struct Small f0() ; { ; struct Small s = { 132 }; ; return s; ; } ; ; struct Big f1() ; { ; struct Big b = { 7171LL, 99LL, -99LL, -3102LL, 32 }; ; return b; ; } ; ; int main() ; { ; struct Small s = f0(); ; struct Big b = f1(); ; return b.j + b.k + b.m + s.x; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 f0: 0: ff 83 00 d1 sub sp, sp, #32 ; | 4: fe 0b 00 f9 str x30, [sp, #16] ; | prolog 8: 08 00 00 90 adrp x8, #0 ; compute addr to storage map (probably to #132) c: 08 01 00 91 add x8, x8, #0 ; addr offset (pointless) 10: e2 03 40 b2 orr x2, xzr, #0x1 ; @@@ unsure, #1 -> x2 14: e9 3f 00 91 add x9, sp, #15 ; addr to #132 -> x9 @@@? 18: e0 03 09 aa mov x0, x9 ; @@@ unsure 1c: e1 03 08 aa mov x1, x8 ; @@@ unsure 20: e9 03 00 f9 str x9, [sp] ; store addr to #132 to top of stack 24: 00 00 00 94 bl #0 <f0+0x24> ; @@@unsure 28: e8 03 40 f9 ldr x8, [sp] ; *sp -> x8 2c: 0a 01 40 39 ldrb w10, [x8] ; *x8 -> w10 30: e9 03 0a 2a mov w9, w10 ; w10 -> w9 34: 20 1d 40 d3 ubfx x0, x9, #0, #8 ; return value ("Unsigned Bit Field Extract", copy 8 bits from x9's LSBits starting at bit 0 to x0, and zero extend; = struct in reg) 38: fe 0b 40 f9 ldr x30, [sp, #16] ; | 3c: ff 83 00 91 add sp, sp, #32 ; | epilog 40: c0 03 5f d6 ret ; | 0000000000000044 f1: 44: ff 03 01 d1 sub sp, sp, #64 ; | 48: fe 1b 00 f9 str x30, [sp, #48] ; | prolog 4c: 09 00 80 52 mov w9, #0 ; @@@ unsure 50: 02 05 80 d2 mov x2, #40 ; @@@ unsure 54: 6a 80 83 d2 mov x10, #7171 ; | i 58: 6b 0c 80 d2 mov x11, #99 ; | j 5c: 4c 0c 80 92 mov x12, #-99 ; | prep local struct Big's data k 60: ad 83 81 92 mov x13, #-3102 ; | l 64: ee 03 7b b2 orr x14, xzr, #0x20 ; | m 68: e0 03 08 aa mov x0, x8 ; retval: ptr to retval -> x0 6c: e1 03 09 2a mov w1, w9 ; @@@ unsure 70: e8 17 00 f9 str x8, [sp, #40] ; ptr to retval -> local area as temp copy 74: ea 13 00 f9 str x10, [sp, #32] ; | i 78: eb 0f 00 f9 str x11, [sp, #24] ; | j 7c: ec 0b 00 f9 str x12, [sp, #16] ; | write struct A to local area k @@@ but in reverse? 80: ed 07 00 f9 str x13, [sp, #8] ; | l 84: ee 03 00 f9 str x14, [sp] ; | m 88: 00 00 00 94 bl #0 <f1+0x44> ; @@@ unsure 8c: e8 13 40 f9 ldr x8, [sp, #32] ; | i -> x8 90: ea 17 40 f9 ldr x10, [sp, #40] ; | ptr to retval -> x10, for below indirections 94: 48 01 00 f9 str x8, [x10] ; | i 98: eb 0f 40 f9 ldr x11, [sp, #24] ; | | j 9c: 4b 05 00 f9 str x11, [x10, #8] ; | / a0: ec 0b 40 f9 ldr x12, [sp, #16] ; | write retval data \ k a4: 4c 09 00 f9 str x12, [x10, #16] ; | / a8: ed 07 40 f9 ldr x13, [sp, #8] ; | \ l ac: 4d 0d 00 f9 str x13, [x10, #24] ; | / b0: ee 03 40 f9 ldr x14, [sp] ; | \ m b4: 4e 11 00 f9 str x14, [x10, #32] ; / / b8: fe 1b 40 f9 ldr x30, [sp, #48] ; \ bc: ff 03 01 91 add sp, sp, #64 ; | epilog c0: c0 03 5f d6 ret ; | 00000000000000c4 main: c4: ff 43 01 d1 sub sp, sp, #80 ; c8: fd 7b 04 a9 stp x29, x30, [sp, #64] ; cc: fd 03 01 91 add x29, sp, #64 ; d0: a8 17 00 d1 sub x8, x29, #5 ; d4: e9 43 00 91 add x9, sp, #16 ; d8: bf c3 1f b8 stur wzr, [x29, #-4] ; dc: e8 07 00 f9 str x8, [sp, #8] ; e0: e9 03 00 f9 str x9, [sp] ; e4: c7 ff ff 97 bl #-228 <f0> ; return address -> r30/lr, and call e8: ea 03 00 2a mov w10, w0 ; ec: e8 07 40 f9 ldr x8, [sp, #8] ; f0: 0a 01 00 39 strb w10, [x8] ; f4: e8 03 40 f9 ldr x8, [sp] ; ptr to retval struct, as sizeof(struct Big) > 16 f8: d3 ff ff 97 bl #-180 <f1> ; return address -> r30/lr, and call fc: e8 0f 40 f9 ldr x8, [sp, #24] ; 100: e9 13 40 f9 ldr x9, [sp, #32] ; 104: 08 01 09 8b add x8, x8, x9 ; 108: e9 1b 40 f9 ldr x9, [sp, #48] ; 10c: 08 01 09 8b add x8, x8, x9 ; 110: e9 07 40 f9 ldr x9, [sp, #8] ; 114: 2a 01 40 39 ldrb w10, [x9] ; 118: e0 03 0a 2a mov w0, w10 ; 11c: 00 1c 40 d3 ubfx x0, x0, #0, #8 ; 120: 08 01 00 8b add x8, x8, x0 ; 124: ea 03 08 2a mov w10, w8 ; 128: e0 03 0a 2a mov w0, w10 ; 12c: fd 7b 44 a9 ldp x29, x30, [sp, #64] ; 130: ff 43 01 91 add sp, sp, #80 ; 134: c0 03 5f d6 ret ; ; output from godbolt compiler explorer w/ msvc 19.14 |f0| PROC |$LN3| sub sp,sp,#0x10 ; mov w8,#-0x7C ; (signed) #132 strb w8,[sp] ; stored in local area ldrb w0,[sp] ; return value (entire struct in reg) add sp,sp,#0x10 ; ret ; ENDP ; |f0| |f1| PROC |$LN3| stp fp,lr,[sp,#-0x10]! ; mov fp,sp ; bl __security_push_cookie ; sub sp,sp,#0x30 ; str x8,[sp] ; ptr to retval -> local area as temp copy mov x9,#0x1C03 ; str x9,[sp,#8] ; mov x8,#0x63 ; str x8,[sp,#0x10] ; mov x8,#-0x63 ; str x8,[sp,#0x18] ; mov x8,#-0xC1E ; str x8,[sp,#0x20] ; mov w8,#0x20 ; str w8,[sp,#0x28] ; ldr x11,[sp] ; ptr to retval -> x11, for below indirections add x10,sp,#8 ; read ptr ldp x9,x8,[x10] ; | | i, j stp x9,x8,[x11] ; | / ldp x9,x8,[x10,#0x10] ; | cp struct data to retval \ k, l stp x9,x8,[x11,#0x10] ; | / ldr x8,[x10,#0x20] ; | \ str x8,[x11,#0x20] ; | | m add sp,sp,#0x30 ; bl __security_pop_cookie ; ldp fp,lr,[sp],#0x10 ; ret ; ENDP ; |f1| |main| PROC |$LN3| stp fp,lr,[sp,#-0x10]! ; mov fp,sp ; bl __security_push_cookie ; sub sp,sp,#0x80 ; bl f0 ; return address -> r30/lr, and call strb w0,[sp] ; add x9,sp,#1 ; mov x8,sp ; ldrsb w8,[x8] ; strb w8,[x9] ; add x8,sp,#0x10 ; ptr to retval struct, as sizeof(struct Big) > 16 bl f1 ; return address -> r30/lr, and call add x8,sp,#0x10 ; str x8,[sp,#8] ; add x11,sp,#0x38 ; ldr x10,[sp,#8] ; ldp x9,x8,[x10] ; stp x9,x8,[x11] ; ldp x9,x8,[x10,#0x10] ; stp x9,x8,[x11,#0x10] ; ldr x8,[x10,#0x20] ; str x8,[x11,#0x20] ; add x11,sp,#0x60 ; add x10,sp,#0x38 ; ldp x9,x8,[x10] ; stp x9,x8,[x11] ; ldp x9,x8,[x10,#0x10] ; stp x9,x8,[x11,#0x10] ; ldr x8,[x10,#0x20] ; str x8,[x11,#0x20] ; ldr x9,[sp,#0x68] ; ldr x8,[sp,#0x70] ; add x9,x9,x8 ; ldr w8,[sp,#0x80] ; sxtw x8,w8 ; add x9,x9,x8 ; ldrsb w8,[sp,#1] ; mov w8,w8 ; sxtw x8,w8 ; add x8,x9,x8 ; mov w0,w8 ; mov w0,w0 ; add sp,sp,#0x80 ; bl __security_pop_cookie ; ldp fp,lr,[sp],#0x10 ; ret ; ENDP ; |main| ; ---------- single-field structs by values (and small array fields) ----------> ; ; struct C { char c; }; ; struct S { short s; }; ; struct I { int i; }; ; struct F { float f; }; ; struct D { double d; }; ; ; struct C2 { char c[2]; }; ; struct C3 { char c[3]; }; ; ; void leaf_call(struct C2 a, struct C b, struct S c, struct I d, struct F e, struct D f, struct C3 g) ; { ; } ; ; int main() ; { ; leaf_call((struct C2){{0,1}}, (struct C){2}, (struct S){3}, (struct I){4}, (struct F){5.f}, (struct D){6.}, (struct C3){{7,8,9}}); ; return 0; ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000000000 leaf_call: 0: ff 03 03 d1 sub sp, sp, #192 4: fe 5b 00 f9 str x30, [sp, #176] 8: e8 03 7f b2 orr x8, xzr, #0x2 c: e9 07 40 b2 orr x9, xzr, #0x3 10: ea bb 02 91 add x10, sp, #174 14: eb 83 02 91 add x11, sp, #160 18: ec 7f 02 91 add x12, sp, #159 1c: ed 73 02 91 add x13, sp, #156 20: ee 63 02 91 add x14, sp, #152 24: ef 53 02 91 add x15, sp, #148 28: f0 23 02 91 add x16, sp, #136 2c: f1 17 02 91 add x17, sp, #133 30: f2 e3 01 91 add x18, sp, #120 34: e0 53 00 f9 str x0, [sp, #160] 38: e0 03 0a aa mov x0, x10 3c: e1 3b 00 f9 str x1, [sp, #112] 40: e1 03 0b aa mov x1, x11 44: e2 37 00 f9 str x2, [sp, #104] 48: e2 03 08 aa mov x2, x8 4c: e3 33 00 f9 str x3, [sp, #96] 50: e0 5f 00 bd str s0, [sp, #92] 54: e1 2b 00 fd str d1, [sp, #80] 58: e4 27 00 f9 str x4, [sp, #72] 5c: e9 23 00 f9 str x9, [sp, #64] 60: ec 1f 00 f9 str x12, [sp, #56] 64: ed 1b 00 f9 str x13, [sp, #48] 68: ee 17 00 f9 str x14, [sp, #40] 6c: ef 13 00 f9 str x15, [sp, #32] 70: f0 0f 00 f9 str x16, [sp, #24] 74: f1 0b 00 f9 str x17, [sp, #16] 78: f2 07 00 f9 str x18, [sp, #8] 7c: 00 00 00 94 bl #0 <leaf_call+0x7c> 80: e8 3b 40 f9 ldr x8, [sp, #112] 84: e5 03 08 2a mov w5, w8 88: e9 1f 40 f9 ldr x9, [sp, #56] 8c: 25 01 00 39 strb w5, [x9] 90: ea 37 40 f9 ldr x10, [sp, #104] 94: e5 03 0a 2a mov w5, w10 98: eb 1b 40 f9 ldr x11, [sp, #48] 9c: 65 01 00 79 strh w5, [x11] a0: ec 33 40 f9 ldr x12, [sp, #96] a4: e5 03 0c 2a mov w5, w12 a8: ed 17 40 f9 ldr x13, [sp, #40] ac: a5 01 00 b9 str w5, [x13] b0: e0 5f 40 bd ldr s0, [sp, #92] b4: ee 13 40 f9 ldr x14, [sp, #32] b8: c0 01 00 bd str s0, [x14] bc: e1 2b 40 fd ldr d1, [sp, #80] c0: ef 0f 40 f9 ldr x15, [sp, #24] c4: e1 01 00 fd str d1, [x15] c8: f0 0b 40 f9 ldr x16, [sp, #16] cc: f1 27 40 f9 ldr x17, [sp, #72] d0: f1 3f 00 f9 str x17, [sp, #120] d4: e0 03 10 aa mov x0, x16 d8: e1 07 40 f9 ldr x1, [sp, #8] dc: e2 23 40 f9 ldr x2, [sp, #64] e0: 00 00 00 94 bl #0 <leaf_call+0xe0> e4: fe 5b 40 f9 ldr x30, [sp, #176] e8: ff 03 03 91 add sp, sp, #192 ec: c0 03 5f d6 ret 00000000000000f0 main: f0: ff 83 03 d1 sub sp, sp, #224 f4: f5 5b 00 f9 str x21, [sp, #176] f8: f4 4f 0c a9 stp x20, x19, [sp, #192] fc: fd 7b 0d a9 stp x29, x30, [sp, #208] 100: fd 43 03 91 add x29, sp, #208 104: 00 00 80 52 mov w0, #0 108: 08 00 80 52 mov w8, #0 10c: e9 03 40 b2 orr x9, xzr, #0x1 110: ea 03 00 32 orr w10, wzr, #0x1 114: eb 03 1f 32 orr w11, wzr, #0x2 118: ec 07 00 32 orr w12, wzr, #0x3 11c: ed 03 1e 32 orr w13, wzr, #0x4 120: 0e 14 a8 52 mov w14, #1084227584 124: c0 01 27 1e fmov s0, w14 128: 0f 03 e8 d2 mov x15, #4618441417868443648 12c: e1 01 67 9e fmov d1, x15 130: ee 0b 00 32 orr w14, wzr, #0x7 134: f0 03 1d 32 orr w16, wzr, #0x8 138: 31 01 80 52 mov w17, #9 13c: e2 03 7f b2 orr x2, xzr, #0x2 140: ef 07 40 b2 orr x15, xzr, #0x3 144: b2 9b 00 d1 sub x18, x29, #38 148: a1 9f 00 d1 sub x1, x29, #39 14c: a3 ab 00 d1 sub x3, x29, #42 150: a4 c3 00 d1 sub x4, x29, #48 154: a5 d3 00 d1 sub x5, x29, #52 158: a6 03 01 d1 sub x6, x29, #64 15c: a7 0f 01 d1 sub x7, x29, #67 160: b3 43 01 d1 sub x19, x29, #80 164: b4 63 01 d1 sub x20, x29, #88 168: bf c3 1d b8 stur wzr, [x29, #-36] 16c: f5 03 12 aa mov x21, x18 170: a8 02 00 39 strb w8, [x21] 174: aa 06 00 39 strb w10, [x21, #1] 178: 2b 00 00 39 strb w11, [x1] 17c: 6c 00 00 79 strh w12, [x3] 180: 8d 00 00 b9 str w13, [x4] 184: a0 00 00 bd str s0, [x5] 188: c1 00 00 fd str d1, [x6] 18c: f5 03 07 aa mov x21, x7 190: ae 02 00 39 strb w14, [x21] 194: a9 02 09 8b add x9, x21, x9 198: b0 06 00 39 strb w16, [x21, #1] 19c: 31 05 00 39 strb w17, [x9, #1] 1a0: a0 43 1a b8 stur w0, [x29, #-92] 1a4: e0 03 13 aa mov x0, x19 1a8: e1 37 00 f9 str x1, [sp, #104] 1ac: e1 03 12 aa mov x1, x18 1b0: ef 33 00 f9 str x15, [sp, #96] 1b4: e3 2f 00 f9 str x3, [sp, #88] 1b8: e4 2b 00 f9 str x4, [sp, #80] 1bc: e5 27 00 f9 str x5, [sp, #72] 1c0: e6 23 00 f9 str x6, [sp, #64] 1c4: e7 1f 00 f9 str x7, [sp, #56] 1c8: f4 1b 00 f9 str x20, [sp, #48] 1cc: 00 00 00 94 bl #0 <main+0xdc> 1d0: a0 03 5b f8 ldur x0, [x29, #-80] 1d4: e9 37 40 f9 ldr x9, [sp, #104] 1d8: 28 01 40 39 ldrb w8, [x9] 1dc: ef 03 08 2a mov w15, w8 1e0: e1 1d 40 d3 ubfx x1, x15, #0, #8 1e4: ef 2f 40 f9 ldr x15, [sp, #88] 1e8: e8 01 40 79 ldrh w8, [x15] 1ec: f2 03 08 2a mov w18, w8 1f0: 42 3e 40 d3 ubfx x2, x18, #0, #16 1f4: f2 2b 40 f9 ldr x18, [sp, #80] 1f8: 48 02 40 b9 ldr w8, [x18] 1fc: e3 03 08 2a mov w3, w8 200: 63 7c 40 d3 ubfx x3, x3, #0, #32 204: e4 27 40 f9 ldr x4, [sp, #72] 208: 80 00 40 bd ldr s0, [x4] 20c: e5 23 40 f9 ldr x5, [sp, #64] 210: a1 00 40 fd ldr d1, [x5] 214: e6 1f 40 f9 ldr x6, [sp, #56] 218: e7 1b 40 f9 ldr x7, [sp, #48] 21c: e0 17 00 f9 str x0, [sp, #40] 220: e0 03 07 aa mov x0, x7 224: e1 13 00 f9 str x1, [sp, #32] 228: e1 03 06 aa mov x1, x6 22c: e6 33 40 f9 ldr x6, [sp, #96] 230: e2 0f 00 f9 str x2, [sp, #24] 234: e2 03 06 aa mov x2, x6 238: e3 0b 00 f9 str x3, [sp, #16] 23c: e0 0f 00 bd str s0, [sp, #12] 240: e1 03 00 fd str d1, [sp] 244: 00 00 00 94 bl #0 <main+0x154> 248: a4 83 5a f8 ldur x4, [x29, #-88] 24c: e0 17 40 f9 ldr x0, [sp, #40] 250: e1 13 40 f9 ldr x1, [sp, #32] 254: e2 0f 40 f9 ldr x2, [sp, #24] 258: e3 0b 40 f9 ldr x3, [sp, #16] 25c: e0 0f 40 bd ldr s0, [sp, #12] 260: e1 03 40 fd ldr d1, [sp] 264: 67 ff ff 97 bl #-612 <leaf_call> 268: a0 43 5a b8 ldur w0, [x29, #-92] 26c: fd 7b 4d a9 ldp x29, x30, [sp, #208] 270: f4 4f 4c a9 ldp x20, x19, [sp, #192] 274: f5 5b 40 f9 ldr x21, [sp, #176] 278: ff 83 03 91 add sp, sp, #224 27c: c0 03 5f d6 ret ; ---------- C++ trivial and non-trivial aggrs passed to C funcs ----------> ; ; struct Trivial { int a; }; ; struct NonTrivial { int a; NonTrivial() : a(0) {} NonTrivial(const NonTrivial& rhs) : a(rhs.a) { } }; ; ; extern "C" { ; ; void f1(struct Trivial s) { } ; void f2(struct NonTrivial s) { } ; ; void f() ; { ; struct Trivial t; ; struct NonTrivial n; ; int a=1; ; a += 123; ; f1(t); ; a -= 123; ; f2(n); ; a -= 12; ; } ; } ; output from freebsd-13.0_r348764-arm64 w/ clang 8.0.0 0000000000210250 f1: 210250: ff 43 00 d1 sub sp, sp, #16 210254: e8 33 00 91 add x8, sp, #12 210258: e9 03 00 2a mov w9, w0 21025c: 09 01 00 b9 str w9, [x8] 210260: ff 43 00 91 add sp, sp, #16 210264: c0 03 5f d6 ret 0000000000210268 f2: 210268: c0 03 5f d6 ret 000000000021026c f: 21026c: ff 43 01 d1 sub sp, sp, #80 ; 210270: fd 7b 04 a9 stp x29, x30, [sp, #64] ; 210274: fd 03 01 91 add x29, sp, #64 ; 210278: e8 03 00 32 orr w8, wzr, #0x1 ; 21027c: e2 03 7e b2 orr x2, xzr, #0x4 ; 210280: a1 13 00 d1 sub x1, x29, #4 ; 210284: a9 23 00 d1 sub x9, x29, #8 ; 210288: aa 43 00 d1 sub x10, x29, #16 ; 21028c: ab 53 00 d1 sub x11, x29, #20 ; 210290: e0 03 09 aa mov x0, x9 ; 210294: a8 83 1e b8 stur w8, [x29, #-24] ; 210298: e2 13 00 f9 str x2, [sp, #32] ; 21029c: e1 0f 00 f9 str x1, [sp, #24] ; 2102a0: e9 0b 00 f9 str x9, [sp, #16] ; 2102a4: ea 07 00 f9 str x10, [sp, #8] ; 2102a8: eb 03 00 f9 str x11, [sp] ; 2102ac: 1f 00 00 94 bl #124 <_ZN10NonTrivialC2Ev> ; 2102b0: a8 83 5e b8 ldur w8, [x29, #-24] ; 2102b4: a8 43 1f b8 stur w8, [x29, #-12] ; 2102b8: ac 43 5f b8 ldur w12, [x29, #-12] ; 2102bc: 8c ed 01 11 add w12, w12, #123 ; 2102c0: ac 43 1f b8 stur w12, [x29, #-12] ; 2102c4: e0 07 40 f9 ldr x0, [sp, #8] ; 2102c8: e1 0f 40 f9 ldr x1, [sp, #24] ; 2102cc: e2 13 40 f9 ldr x2, [sp, #32] ; 2102d0: 50 00 00 94 bl #320 <memcpy@plt> ; 2102d4: e9 07 40 f9 ldr x9, [sp, #8] ; 2102d8: 28 01 40 b9 ldr w8, [x9] ; 2102dc: ea 03 08 2a mov w10, w8 ; 2102e0: 40 7d 40 d3 ubfx x0, x10, #0, #32 ; 2102e4: db ff ff 97 bl #-148 <f1> ; 2102e8: a8 43 5f b8 ldur w8, [x29, #-12] ; 2102ec: 08 ed 01 71 subs w8, w8, #123 ; 2102f0: a8 43 1f b8 stur w8, [x29, #-12] ; 2102f4: e0 03 40 f9 ldr x0, [sp] ; | ptr to dest of copy of n 2102f8: e1 0b 40 f9 ldr x1, [sp, #16] ; | copy n ptr to n 2102fc: 11 00 00 94 bl #68 <_ZN10NonTrivialC2ERKS_> ; | NonTrivial::NonTrivial(const NonTrivial&) / copy ctor 210300: e0 03 40 f9 ldr x0, [sp] ; f2 arg 0 (ptr to copy of struct NonTrivial), via ptr as non-trivial 210304: d9 ff ff 97 bl #-156 <f2> ; call f2(struct NonTrivial) 210308: a8 43 5f b8 ldur w8, [x29, #-12] ; 21030c: 08 31 00 71 subs w8, w8, #12 ; 210310: a8 43 1f b8 stur w8, [x29, #-12] ; 210314: fd 7b 44 a9 ldp x29, x30, [sp, #64] ; 210318: ff 43 01 91 add sp, sp, #80 ; 21031c: c0 03 5f d6 ret ; ; ... snip, removed code of ctor and copy ctor ... ; vim: ft=asm68k