diff options
| author | Sanjay Patel <spatel@rotateright.com> | 2017-01-08 15:53:40 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2017-01-08 15:53:40 +0000 |
| commit | bf51c8a975621c6c275612bfe6d7b8d833c6b83b (patch) | |
| tree | 56eea9b17d69e26cc37a6d5d4c9ba3f7e08f2ce0 /llvm/test | |
| parent | 9c58950eeb0ac0ffe86b0ebdd43b2042d4fb9de6 (diff) | |
| download | bcm5719-llvm-bf51c8a975621c6c275612bfe6d7b8d833c6b83b.tar.gz bcm5719-llvm-bf51c8a975621c6c275612bfe6d7b8d833c6b83b.zip | |
[x86] fix usage of stale operands when lowering select
I noticed this problem as part of the ongoing attempt to canonicalize min/max ops in IR.
The debug output shows nodes like this:
t4: i32 = xor t2, Constant:i32<-1>
t21: i8 = setcc t4, Constant:i32<0>, setlt:ch
t14: i32 = select t21, t4, Constant:i32<-1>
And because the select is holding onto the t4 (xor) node while EmitTest creates a new
x86-specific xor node, the lowering results in:
t4: i32 = xor t2, Constant:i32<-1>
t25: i32,i32 = X86ISD::XOR t2, Constant:i32<-1>
t28: i32,glue = X86ISD::CMOV Constant:i32<-1>, t4, Constant:i8<15>, t25:1
Differential Revision: https://reviews.llvm.org/D28374
llvm-svn: 291392
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/CodeGen/X86/cmov.ll | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/llvm/test/CodeGen/X86/cmov.ll b/llvm/test/CodeGen/X86/cmov.ll index 8e9bc8b5af4..0060539c691 100644 --- a/llvm/test/CodeGen/X86/cmov.ll +++ b/llvm/test/CodeGen/X86/cmov.ll @@ -157,16 +157,12 @@ define i8 @test7(i1 inreg %c, i8 inreg %a, i8 inreg %b) nounwind { ret i8 %d } -; FIXME: The 'not' is redundant. - define i32 @smin(i32 %x) { ; CHECK-LABEL: smin: ; CHECK: ## BB#0: -; CHECK-NEXT: movl %edi, %ecx -; CHECK-NEXT: notl %ecx ; CHECK-NEXT: xorl $-1, %edi ; CHECK-NEXT: movl $-1, %eax -; CHECK-NEXT: cmovsl %ecx, %eax +; CHECK-NEXT: cmovsl %edi, %eax ; CHECK-NEXT: retq %not_x = xor i32 %x, -1 %1 = icmp slt i32 %not_x, -1 |
