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author | Evan Cheng <evan.cheng@apple.com> | 2010-11-22 18:12:04 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2010-11-22 18:12:04 +0000 |
commit | ab5c703fdb0b07c6d89271519fd1cca7105b3eae (patch) | |
tree | 52b8ff64598ea781f1e347405867c74989a11920 /test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll | |
parent | 4d5a29979000e1d5afc6c31239fe12d888027f4c (diff) | |
download | external_llvm-ab5c703fdb0b07c6d89271519fd1cca7105b3eae.zip external_llvm-ab5c703fdb0b07c6d89271519fd1cca7105b3eae.tar.gz external_llvm-ab5c703fdb0b07c6d89271519fd1cca7105b3eae.tar.bz2 |
Fix epilogue codegen to avoid leaving the stack pointer in an invalid
state. Previously Thumb2 would restore sp from fp like this:
mov sp, r7
sub, sp, #4
If an interrupt is taken after the 'mov' but before the 'sub', callee-saved
registers might be clobbered by the interrupt handler. Instead, try
restoring directly from sp:
add sp, #4
Or, if necessary (with VLA, etc.) use a scratch register to compute sp and
then restore it:
sub.w r4, r7, #8
mov sp, r7
rdar://8465407
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119977 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll')
-rw-r--r-- | test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll b/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll new file mode 100644 index 0000000..313728c --- /dev/null +++ b/test/CodeGen/Thumb2/2010-11-22-EpilogueBug.ll @@ -0,0 +1,34 @@ +; rdar://8465407 +; RUN: llc < %s -mtriple=thumbv7-apple-darwin | FileCheck %s + +%struct.buf = type opaque + +declare void @bar() nounwind optsize + +define void @foo() nounwind optsize { +; CHECK: foo: +; CHECK: push +; CHECK: add r7, sp, #4 +; CHECK: sub sp, #4 +entry: + %m.i = alloca %struct.buf*, align 4 + br label %bb + +bb: + br i1 undef, label %bb3, label %bb2 + +bb2: + call void @bar() nounwind optsize + br i1 undef, label %bb, label %bb3 + +bb3: + br i1 undef, label %return, label %bb + +return: +; CHECK: %return +; 'mov sp, r7' would have left sp in an invalid state +; CHECK-NOT: mov sp, r7 +; CHECK-NOT: sub, sp, #4 +; CHECK: add sp, #4 + ret void +} |