[llvm-commits] [llvm] r48515 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/x86-64-varargs.ll

[Evan Cheng]

Author: evancheng
Date: Tue Mar 18 18:36:35 2008
New Revision: 48515

URL: http://llvm.org/viewvc/llvm-project?rev=48515&view=rev
Log:
Fix a x86-64 isel lowering bug that's been around forever. A x86-64 varargs function implicitly reads X86::AL, don't clobber it!

Added:
    llvm/trunk/test/CodeGen/X86/x86-64-varargs.ll
Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=48515&r1=48514&r2=48515&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Mar 18 18:36:35 2008
@@ -1746,18 +1746,22 @@
   if (IsTailCall)
     Ops.push_back(DAG.getConstant(FPDiff, MVT::i32));
 
-  // Add an implicit use GOT pointer in EBX.
-  if (!IsTailCall && !Is64Bit &&
-      getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
-      Subtarget->isPICStyleGOT())
-    Ops.push_back(DAG.getRegister(X86::EBX, getPointerTy()));
-
   // Add argument registers to the end of the list so that they are known live
   // into the call.
   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                   RegsToPass[i].second.getValueType()));
   
+  // Add an implicit use GOT pointer in EBX.
+  if (!IsTailCall && !Is64Bit &&
+      getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
+      Subtarget->isPICStyleGOT())
+    Ops.push_back(DAG.getRegister(X86::EBX, getPointerTy()));
+
+  // Add an implicit use of AL for x86 vararg functions.
+  if (Is64Bit && isVarArg)
+    Ops.push_back(DAG.getRegister(X86::AL, MVT::i8));
+
   if (InFlag.Val)
     Ops.push_back(InFlag);
 

Added: llvm/trunk/test/CodeGen/X86/x86-64-varargs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/x86-64-varargs.ll?rev=48515&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/x86-64-varargs.ll (added)
+++ llvm/trunk/test/CodeGen/X86/x86-64-varargs.ll Tue Mar 18 18:36:35 2008
@@ -0,0 +1,11 @@
+; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin -code-model=large -relocation-model=static | grep call | not grep rax
+
+ at .str = internal constant [26 x i8] c"%d, %f, %d, %lld, %d, %f\0A\00"		; <[26 x i8]*> [#uses=1]
+
+declare i32 @printf(i8*, ...) nounwind 
+
+define i32 @main() nounwind  {
+entry:
+	%tmp10.i = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([26 x i8]* @.str, i32 0, i64 0), i32 12, double 0x3FF3EB8520000000, i32 120, i64 123456677890, i32 -10, double 4.500000e+15 ) nounwind 		; <i32> [#uses=0]
+	ret i32 0
+}