[llvm] r321801 - [InstCombine] safely create a constant of the right type (PR35794)

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Thu Jan  4 06:31:56 2018
New Revision: 321801

URL: http://llvm.org/viewvc/llvm-project?rev=321801&view=rev
Log:
[InstCombine] safely create a constant of the right type (PR35794)

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/trunk/test/Transforms/InstCombine/icmp.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=321801&r1=321800&r2=321801&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Thu Jan  4 06:31:56 2018
@@ -4082,13 +4082,13 @@ Instruction *InstCombiner::foldICmpUsing
     computeUnsignedMinMaxValuesFromKnownBits(Op1Known, Op1Min, Op1Max);
   }
 
-  // If Min and Max are known to be the same, then SimplifyDemandedBits
-  // figured out that the LHS is a constant. Constant fold this now, so that
+  // If Min and Max are known to be the same, then SimplifyDemandedBits figured
+  // out that the LHS or RHS is a constant. Constant fold this now, so that
   // code below can assume that Min != Max.
   if (!isa<Constant>(Op0) && Op0Min == Op0Max)
-    return new ICmpInst(Pred, ConstantInt::get(Op0->getType(), Op0Min), Op1);
+    return new ICmpInst(Pred, ConstantExpr::getIntegerValue(Ty, Op0Min), Op1);
   if (!isa<Constant>(Op1) && Op1Min == Op1Max)
-    return new ICmpInst(Pred, Op0, ConstantInt::get(Op1->getType(), Op1Min));
+    return new ICmpInst(Pred, Op0, ConstantExpr::getIntegerValue(Ty, Op1Min));
 
   // Based on the range information we know about the LHS, see if we can
   // simplify this comparison.  For example, (x&4) < 8 is always true.

Modified: llvm/trunk/test/Transforms/InstCombine/icmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/icmp.ll?rev=321801&r1=321800&r2=321801&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/icmp.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/icmp.ll Thu Jan  4 06:31:56 2018
@@ -3286,3 +3286,19 @@ define i32 @abs_preserve(i32 %x) {
   %abs = select i1 %c, i32 %a, i32 %nega
   ret i32 %abs
 }
+
+; Don't crash by assuming the compared values are integers.
+
+declare void @llvm.assume(i1)
+define i1 @PR35794(i32* %a) {
+; CHECK-LABEL: @PR35794(
+; CHECK-NEXT:    [[MASKCOND:%.*]] = icmp eq i32* %a, null
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[MASKCOND]])
+; CHECK-NEXT:    ret i1 true
+;
+  %cmp = icmp sgt i32* %a, inttoptr (i64 -1 to i32*)
+  %maskcond = icmp eq i32* %a, null
+  tail call void @llvm.assume(i1 %maskcond)
+  ret i1 %cmp
+}
+