<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/62115>62115</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
Miscompilation with -tailcallopt
</td>
</tr>
<tr>
<th>Labels</th>
<td>
new issue
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
sillycross
</td>
</tr>
</table>
<pre>
Reduced test case:
test.ll:
```
source_filename = "test"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define void @deegen_baseline_jit_do_codegen_impl(ptr nocapture readonly %0) local_unnamed_addr #0 {
tail call ghccc void %0() #0
ret void
}
attributes #0 = { nounwind }
!llvm.linker.options = !{}
!llvm.ident = !{!0}
!llvm.module.flags = !{!1, !2}
!0 = !{!"clang version 15.0.3 (https://github.com/llvm/llvm-project.git 4a2c05b05ed07f1f620e94f6524a8b4b2760a0b1)"}
!1 = !{i32 1, !"wchar_size", i32 4}
!2 = !{i32 7, !"uwtable", i32 2}
```
Command (LLVM 15.0.3):
```
llc-15 test.ll -o test.s -O3
```
generates correct output:
```
pushq %rbp
pushq %r15
pushq %r14
pushq %r13
pushq %r12
pushq %rbx
pushq %rax
callq *%rdi
addq $8, %rsp
popq %rbx
popq %r12
popq %r13
popq %r14
popq %r15
popq %rbp
retq
```
But command
```
llc-15 test.ll -o test.s -O3 -tailcallopt
```
generates bad output
```
pushq %rbp
pushq %r15
pushq %r14
pushq %r13
pushq %r12
pushq %rbx
pushq %rax
callq *%rdi
popq %rbx
popq %r12
popq %r13
popq %r14
popq %r15
popq %rbp
retq
```
Note that assembly line `addq $8, %rsp` is gone, and stack is no longer balanced after the call.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzcVk-P46gT_TTkghzhMnbsQw79R32a-f2kXWmvEYaKwzQGD-BO9376FY7Tcfd4djW31UoRgVf1XA_8AIsQdGcR96S8J-XjRozx5Pw-aGPepHchbFqn3va_oRolKhoxRCpFQFLcEfZI2NwmfGvMDa3Y_JuGwY1e4uGoDVrRIyXFIyUAiUUA5kcI32GkSkRhxJsb4zULs54Ud5gNsGOkuCtgatIw_zhMvYpPTaavnWOdSDnUma1Tp7pyKp79nkP9uX70ejDvCl_r6lDxbLTP1p1tZrQdX7POju-sS6vwqC3SF6cVJZwpxA7toRUBjbZ4-KbjQbmDdGrCdT8YAvUQPbVOiiGOHqlHoZw1b5RAyQg01DgpzGG0acHUQSjlKYGCUbK7vxSlNAptqBTG0O4kpZzrT_w6PSLlX3M9xik-y949LvWLGL1ux4hhrpFmv7un1o32rK2in_IJ5Ma89Fuj7TP6rRuidjbMi5Ynhe_5c6ZWaOMyAXL2Q1Lv1GhwezSiCx9zcwIPaQQ_CmEfMwmANMJ29AV90M7SvNyybUEJ1KcYh5AsCk8EnjodT2O7la4n8JTKz3_Z4N03lHHb6Ui5AMnKlpWo2O6YHytg2PBjVQIXdctb2FVMsDYn0CRLLCaUL2TpAuh1BgTgLE_CH4L-ExMHHmiK8yUZPpF3N_J4jqI1S-ai7Mddd2kfXN-L9Aqh_vLlj6_zeiTBP9msxsgsL-m8pWnmLt1As_8XdJXRoUUvknuk8x5lpG6Mwxh_VoGwZhjD6TthDYHSt8MqnJfrMF-Hi3UY1ku-rsLiBqdtdYHvUkTp94hQ6hLg9eW1lD4sZuCGtSI3dKlogRarKF9Fy9VqNw0e4_e_ccT9GKm8uOLXDZClQyctjhviP5ihFepqhP-eC_7V7_l_LiKNJxGpCAH71rzRdBFRUrF191aM6kA7ZzGB6bgIUcjnBFpHjbMdetoKI2z6ChDHiJ7GE06Xz3bprY3aF6opGrHBfV7VeVHzuobNaV-wmvFC8R3fIavaumxl1VTVUe44w1a1G70HBgXjeZHnkANsueK1lLJqlGwaxhvCGfZCm-10VzjfbXQII-4ryPNyY0SLJkyfMQAWz3QKpmOyfNz4_XSyt2MXCGdGhxhuT4k6Gtx_1UG6ftBGpLuMnnU8ffD6ZvRm_2s3CIGnSUQg8DSJ_CsAAP__unCYmg">