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
diff --git a/test/CodeGen/ARM/hello.ll b/test/CodeGen/ARM/hello.ll
index ccdc7bf..bfed7a6 100644
--- a/test/CodeGen/ARM/hello.ll
+++ b/test/CodeGen/ARM/hello.ll
@@ -1,7 +1,7 @@
; RUN: llc < %s -march=arm
; RUN: llc < %s -mtriple=arm-linux-gnueabi | grep mov | count 1
; RUN: llc < %s -mtriple=arm-linux-gnu --disable-fp-elim | \
-; RUN: grep mov | count 3
+; RUN: grep mov | count 2
; RUN: llc < %s -mtriple=arm-apple-darwin | grep mov | count 2
@str = internal constant [12 x i8] c"Hello World\00"