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| author | Wei Mi <wmi@google.com> | 2017-09-06 16:05:17 +0000 |
|---|---|---|
| committer | Wei Mi <wmi@google.com> | 2017-09-06 16:05:17 +0000 |
| commit | 818d50a93dbeb4a62140f72a0f89d0295b461177 (patch) | |
| tree | 1147a985412f129c26a758f8c1c4ea11be028827 /llvm/test/CodeGen/X86 | |
| parent | 949fac9e40bf6dce04220a7a9b53bb36727e7f56 (diff) | |
| download | bcm5719-llvm-818d50a93dbeb4a62140f72a0f89d0295b461177.tar.gz bcm5719-llvm-818d50a93dbeb4a62140f72a0f89d0295b461177.zip | |
[TailCall] Allow llvm.memcpy/memset/memmove to be tail calls when parent
function return the intrinsics's first argument.
llvm.memcpy/memset/memmove return void but they will return the first
argument after they are expanded as libcalls. Now if the parent function
has any return value, llvm.memcpy cannot be turned into tail call after
expansion.
The patch is to handle that case in SelectionDAGBuilder so when caller
function return the same value as the first argument of llvm.memcpy,
tail call is allowed.
Differential Revision: https://reviews.llvm.org/D37406
llvm-svn: 312641
Diffstat (limited to 'llvm/test/CodeGen/X86')
| -rw-r--r-- | llvm/test/CodeGen/X86/tailcall-mem-intrinsics.ll | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/tailcall-mem-intrinsics.ll b/llvm/test/CodeGen/X86/tailcall-mem-intrinsics.ll index 8e1e4f464ba..7491ea659ba 100644 --- a/llvm/test/CodeGen/X86/tailcall-mem-intrinsics.ll +++ b/llvm/test/CodeGen/X86/tailcall-mem-intrinsics.ll @@ -24,6 +24,30 @@ entry: ret void } +; CHECK-LABEL: tail_memcpy_ret +; CHECK: jmp memcpy +define i8* @tail_memcpy_ret(i8* nocapture %p, i8* nocapture readonly %q, i32 %n) #0 { +entry: + tail call void @llvm.memcpy.p0i8.p0i8.i32(i8* %p, i8* %q, i32 %n, i32 1, i1 false) + ret i8* %p +} + +; CHECK-LABEL: tail_memmove_ret +; CHECK: jmp memmove +define i8* @tail_memmove_ret(i8* nocapture %p, i8* nocapture readonly %q, i32 %n) #0 { +entry: + tail call void @llvm.memmove.p0i8.p0i8.i32(i8* %p, i8* %q, i32 %n, i32 1, i1 false) + ret i8* %p +} + +; CHECK-LABEL: tail_memset_ret +; CHECK: jmp memset +define i8* @tail_memset_ret(i8* nocapture %p, i8 %c, i32 %n) #0 { +entry: + tail call void @llvm.memset.p0i8.i32(i8* %p, i8 %c, i32 %n, i32 1, i1 false) + ret i8* %p +} + declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1) #0 declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1) #0 declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) #0 |
