[llvm-commits] [llvm] r48171 - in /llvm/trunk: lib/CodeGen/SelectionDAG/LegalizeDAG.cpp test/CodeGen/X86/mul-legalize.ll

[Dan Gohman]

Author: djg
Date: Mon Mar 10 15:42:19 2008
New Revision: 48171

URL: http://llvm.org/viewvc/llvm-project?rev=48171&view=rev
Log:
Fix mul expansion to check the correct number of bits for
zero extension when checking if an unsigned multiply is
safe.

Added:
    llvm/trunk/test/CodeGen/X86/mul-legalize.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp?rev=48171&r1=48170&r2=48171&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp Mon Mar 10 15:42:19 2008
@@ -6436,10 +6436,9 @@
       unsigned InnerBitSize = RH.getValueSizeInBits();
       unsigned LHSSB = DAG.ComputeNumSignBits(Op.getOperand(0));
       unsigned RHSSB = DAG.ComputeNumSignBits(Op.getOperand(1));
-      if (DAG.MaskedValueIsZero(Op.getOperand(0),
-                                APInt::getHighBitsSet(OuterBitSize, LHSSB)) &&
-          DAG.MaskedValueIsZero(Op.getOperand(1),
-                                APInt::getHighBitsSet(OuterBitSize, RHSSB))) {
+      APInt HighMask = APInt::getHighBitsSet(OuterBitSize, InnerBitSize);
+      if (DAG.MaskedValueIsZero(Node->getOperand(0), HighMask) &&
+          DAG.MaskedValueIsZero(Node->getOperand(1), HighMask)) {
         // The inputs are both zero-extended.
         if (HasUMUL_LOHI) {
           // We can emit a umul_lohi.

Added: llvm/trunk/test/CodeGen/X86/mul-legalize.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/mul-legalize.ll?rev=48171&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/mul-legalize.ll (added)
+++ llvm/trunk/test/CodeGen/X86/mul-legalize.ll Mon Mar 10 15:42:19 2008
@@ -0,0 +1,27 @@
+; RUN: llvm-as < %s | llc -march=x86 | grep cmov | count 1
+; PR2135
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
+target triple = "i386-pc-linux-gnu"
+ at .str = constant [13 x i8] c"c45531m.adb\00\00"		
+
+define void @main() {
+entry:
+	%tmp1 = call i1 @report__equal( i32 3, i32 3 )		
+	%b.0 = select i1 %tmp1, i64 35184372088832, i64 0		
+	%tmp7 = mul i64 3, %b.0		
+	%tmp32 = icmp eq i64 %tmp7, 105553116266496		
+	br i1 %tmp32, label %return, label %bb35
+bb35:		
+	call void @abort( )
+	unreachable
+return:		
+	ret void
+}
+
+define i1 @report__equal(i32 %x, i32 %y) {
+	%tmp = icmp eq i32 %x, %y		
+	ret i1 %tmp
+}
+
+declare void @abort()