diff options
| -rw-r--r-- | lib/Target/X86/X86InstrCompiler.td | 2 | ||||
| -rw-r--r-- | test/CodeGen/X86/2012-01-16-mfence-nosse-flags.ll | 34 |
2 files changed, 35 insertions, 1 deletions
diff --git a/lib/Target/X86/X86InstrCompiler.td b/lib/Target/X86/X86InstrCompiler.td index 5649ba5..1106b85 100644 --- a/lib/Target/X86/X86InstrCompiler.td +++ b/lib/Target/X86/X86InstrCompiler.td @@ -551,7 +551,7 @@ def ATOMSWAP6432 : I<0, Pseudo, (outs GR32:$dst1, GR32:$dst2), // Memory barriers // TODO: Get this to fold the constant into the instruction. -let isCodeGenOnly = 1 in +let isCodeGenOnly = 1, Defs = [EFLAGS] in def OR32mrLocked : I<0x09, MRMDestMem, (outs), (ins i32mem:$dst, GR32:$zero), "lock\n\t" "or{l}\t{$zero, $dst|$dst, $zero}", diff --git a/test/CodeGen/X86/2012-01-16-mfence-nosse-flags.ll b/test/CodeGen/X86/2012-01-16-mfence-nosse-flags.ll new file mode 100644 index 0000000..a883d79 --- /dev/null +++ b/test/CodeGen/X86/2012-01-16-mfence-nosse-flags.ll @@ -0,0 +1,34 @@ +; RUN: llc < %s -mtriple=i686-linux -mattr=-sse | FileCheck %s +; PR11768 + +@ptr = external global i8* + +define void @baz() nounwind ssp { +entry: + %0 = load i8** @ptr, align 4 + %cmp = icmp eq i8* %0, null + fence seq_cst + br i1 %cmp, label %if.then, label %if.else + +; Make sure the fence comes before the comparison, since it +; clobbers EFLAGS. + +; CHECK: lock +; CHECK-NEXT: orl {{.*}}, (%esp) +; CHECK-NEXT: cmpl $0 + +if.then: ; preds = %entry + tail call void bitcast (void (...)* @foo to void ()*)() nounwind + br label %if.end + +if.else: ; preds = %entry + tail call void bitcast (void (...)* @bar to void ()*)() nounwind + br label %if.end + +if.end: ; preds = %if.else, %if.then + ret void +} + +declare void @foo(...) + +declare void @bar(...) |