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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2013-02-13 13:40:35 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2013-02-13 13:40:35 +0000 |
| commit | 8e2637e2b00eea944e8ada6106d3cbf00c46a223 (patch) | |
| tree | c399bbba649e803a1af4d93d580899713e9e9ec2 /llvm/test/CodeGen/X86/stack-align-memcpy.ll | |
| parent | 3c2489e2c32e7d4b29889f14641d2bfaa742c262 (diff) | |
| download | bcm5719-llvm-8e2637e2b00eea944e8ada6106d3cbf00c46a223.tar.gz bcm5719-llvm-8e2637e2b00eea944e8ada6106d3cbf00c46a223.zip | |
X86: Disable generation of rep;movsl when %esi is used as a base pointer.
This happens when there is both stack realignment and a dynamic alloca in the
function. If we overwrite %esi (rep;movsl uses fixed registers) we'll lose the
base pointer and the next register spill will write into oblivion.
Fixes PR15249 and unbreaks firefox on i386/freebsd. Mozilla uses dynamic allocas
and freebsd a 4 byte stack alignment.
llvm-svn: 175057
Diffstat (limited to 'llvm/test/CodeGen/X86/stack-align-memcpy.ll')
| -rw-r--r-- | llvm/test/CodeGen/X86/stack-align-memcpy.ll | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/stack-align-memcpy.ll b/llvm/test/CodeGen/X86/stack-align-memcpy.ll new file mode 100644 index 00000000000..74945e5bb1b --- /dev/null +++ b/llvm/test/CodeGen/X86/stack-align-memcpy.ll @@ -0,0 +1,18 @@ +; RUN: llc < %s -force-align-stack -mtriple i386-apple-darwin -mcpu=i486 | FileCheck %s + +%struct.foo = type { [88 x i8] } + +; PR15249 +; We can't use rep;movsl here because it clobbers the base pointer in %esi. +define void @test1(%struct.foo* nocapture %x, i32 %y) nounwind { + %dynalloc = alloca i8, i32 %y, align 1 + call void @bar(i8* %dynalloc, %struct.foo* align 4 byval %x) + ret void + +; CHECK: test1: +; CHECK: andl $-16, %esp +; CHECK: movl %esp, %esi +; CHECK-NOT: rep;movsl +} + +declare void @bar(i8* nocapture, %struct.foo* align 4 byval) nounwind |
