Fixed a register scavenger bug. If a def is re-defining part of a super register, there must be an implicit def of the super-register on the MI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48024 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 28 insertions, 3 deletions

diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 635e0cc..2535d78 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -29,15 +29,20 @@ using namespace llvm;
 /// part of a super-register.
 static bool RedefinesSuperRegPart(const MachineInstr *MI, unsigned SubReg,
                                   const TargetRegisterInfo *TRI) {
+  bool SeenSuperUse = false;
+  bool SeenSuperDef = false;
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = MI->getOperand(i);
-    if (!MO.isRegister() || !MO.isUse())
+    if (!MO.isRegister())
       continue;
     if (TRI->isSuperRegister(SubReg, MO.getReg()))
-      return true;
+      if (MO.isUse())
+        SeenSuperUse = true;
+      else if (MO.isImplicit())
+        SeenSuperDef = true;
   }
 
-  return false;
+  return SeenSuperDef && SeenSuperUse;
 }
 
 static bool RedefinesSuperRegPart(const MachineInstr *MI,
diff --git a/test/CodeGen/ARM/2008-03-07-RegScavengerAssert.ll b/test/CodeGen/ARM/2008-03-07-RegScavengerAssert.ll
new file mode 100644
index 0000000..70f1774
--- /dev/null
+++ b/test/CodeGen/ARM/2008-03-07-RegScavengerAssert.ll
@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin -mattr=+v6,+vfp2
+
+@accum = external global { double, double }		; <{ double, double }*> [#uses=1]
+@.str = external constant [4 x i8]		; <[4 x i8]*> [#uses=1]
+
+define i32 @main() {
+entry:
+	br label %bb74.i
+bb74.i:		; preds = %bb88.i, %bb74.i, %entry
+	br i1 false, label %bb88.i, label %bb74.i
+bb88.i:		; preds = %bb74.i
+	br i1 false, label %mandel.exit, label %bb74.i
+mandel.exit:		; preds = %bb88.i
+	%tmp2 = volatile load double* getelementptr ({ double, double }* @accum, i32 0, i32 0), align 8		; <double> [#uses=1]
+	%tmp23 = fptosi double %tmp2 to i32		; <i32> [#uses=1]
+	%tmp5 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), i32 %tmp23 )		; <i32> [#uses=0]
+	ret i32 0
+}
+
+declare i32 @printf(i8*, ...)