Merging r196046:

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r196046 | tnorthover | 2013-12-01 06:16:24 -0800 (Sun, 01 Dec 2013) | 8 lines

ARM: fix bug in -Oz stack adjustment folding

Previously, we clobbered callee-saved registers when folding an "add
sp, #N" into a "pop {rD, ...}" instruction. This change checks whether
a register we're going to add to the "pop" could actually be live
outside the function before doing so and should fix the issue.

This should fix PR18081.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@196074 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.h b/lib/Target/ARM/ARMBaseRegisterInfo.h
index 0d4f54f891..e28fff68f4 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.h
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.h
@@ -72,6 +72,14 @@ static inline bool isARMArea3Register(unsigned Reg, bool isIOS) {
   }
 }
 
+static inline bool isCalleeSavedRegister(unsigned Reg,
+                                         const MCPhysReg *CSRegs) {
+  for (unsigned i = 0; CSRegs[i]; ++i)
+    if (Reg == CSRegs[i])
+      return true;
+  return false;
+}
+
 class ARMBaseRegisterInfo : public ARMGenRegisterInfo {
 protected:
   const ARMSubtarget &STI;