[llvm-commits] [llvm] r124167 - in /llvm/trunk: lib/Target/ARM/ARMFrameLowering.cpp test/CodeGen/ARM/call-tc.ll

[Evan Cheng]

Author: evancheng
Date: Mon Jan 24 19:28:33 2011
New Revision: 124167

URL: http://llvm.org/viewvc/llvm-project?rev=124167&view=rev
Log:
Don't merge restore with tail call instruction.

Modified:
    llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp
    llvm/trunk/test/CodeGen/ARM/call-tc.ll

Modified: llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp?rev=124167&r1=124166&r2=124167&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp Mon Jan 24 19:28:33 2011
@@ -586,6 +586,11 @@
   const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   DebugLoc DL = MI->getDebugLoc();
+  unsigned RetOpcode = MI->getOpcode();
+  bool isTailCall = (RetOpcode == ARM::TCRETURNdi ||
+                     RetOpcode == ARM::TCRETURNdiND ||
+                     RetOpcode == ARM::TCRETURNri ||
+                     RetOpcode == ARM::TCRETURNriND);
 
   SmallVector<unsigned, 4> Regs;
   unsigned i = CSI.size();
@@ -596,7 +601,7 @@
       unsigned Reg = CSI[i-1].getReg();
       if (!(Func)(Reg, STI.isTargetDarwin())) continue;
 
-      if (Reg == ARM::LR && !isVarArg && STI.hasV5TOps()) {
+      if (Reg == ARM::LR && !isTailCall && !isVarArg && STI.hasV5TOps()) {
         Reg = ARM::PC;
         LdmOpc = AFI->isThumbFunction() ? ARM::t2LDMIA_RET : ARM::LDMIA_RET;
         // Fold the return instruction into the LDM.

Modified: llvm/trunk/test/CodeGen/ARM/call-tc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/call-tc.ll?rev=124167&r1=124166&r2=124167&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/call-tc.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/call-tc.ll Mon Jan 24 19:28:33 2011
@@ -1,5 +1,6 @@
 ; RUN: llc < %s -mtriple=armv6-apple-darwin -mattr=+vfp2 -arm-tail-calls | FileCheck %s -check-prefix=CHECKV6
 ; RUN: llc < %s -mtriple=armv6-linux-gnueabi -relocation-model=pic -mattr=+vfp2 -arm-tail-calls | FileCheck %s -check-prefix=CHECKELF
+; RUN: llc < %s -mtriple=thumbv7-apple-darwin -arm-tail-calls | FileCheck %s -check-prefix=CHECKT2
 
 @t = weak global i32 ()* null           ; <i32 ()**> [#uses=1]
 
@@ -63,3 +64,24 @@
   %0 = sdiv i32 %a, %b
   ret i32 %0
 }
+
+; Make sure the tail call instruction isn't deleted
+; rdar://8309338
+declare void @foo() nounwind
+
+define void @t7() nounwind {
+entry:
+; CHECKT2: t7:
+; CHECKT2: blxeq _foo
+; CHECKT2-NEXT: pop.w
+; CHECKT2-NEXT: b.w _foo
+  br i1 undef, label %bb, label %bb1.lr.ph
+
+bb1.lr.ph:
+  tail call void @foo() nounwind
+  unreachable
+
+bb:
+  tail call void @foo() nounwind
+  ret void
+}