[llvm] r315130 - [InstCombine] use correct type when propagating constant condition in simplifyDivRemOfSelectWithZeroOp (PR34856)

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Fri Oct  6 16:43:06 2017
New Revision: 315130

URL: http://llvm.org/viewvc/llvm-project?rev=315130&view=rev
Log:
[InstCombine] use correct type when propagating constant condition in simplifyDivRemOfSelectWithZeroOp (PR34856)

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
    llvm/trunk/test/Transforms/InstCombine/udiv_select_to_select_shift.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=315130&r1=315129&r2=315130&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Fri Oct  6 16:43:06 2017
@@ -813,7 +813,7 @@ bool InstCombiner::simplifyDivRemOfSelec
 
   // Scan the current block backward, looking for other uses of SI.
   BasicBlock::iterator BBI = I.getIterator(), BBFront = I.getParent()->begin();
-
+  Type *CondTy = SelectCond->getType();
   while (BBI != BBFront) {
     --BBI;
     // If we found a call to a function, we can't assume it will return, so
@@ -828,7 +828,8 @@ bool InstCombiner::simplifyDivRemOfSelec
         *I = SI->getOperand(NonNullOperand);
         Worklist.Add(&*BBI);
       } else if (*I == SelectCond) {
-        *I = Builder.getInt1(NonNullOperand == 1);
+        *I = NonNullOperand == 1 ? ConstantInt::getTrue(CondTy)
+                                 : ConstantInt::getFalse(CondTy);
         Worklist.Add(&*BBI);
       }
     }

Modified: llvm/trunk/test/Transforms/InstCombine/udiv_select_to_select_shift.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/udiv_select_to_select_shift.ll?rev=315130&r1=315129&r2=315130&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/udiv_select_to_select_shift.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/udiv_select_to_select_shift.ll Fri Oct  6 16:43:06 2017
@@ -19,3 +19,19 @@ define i64 @test(i64 %X, i1 %Cond ) {
   ret i64 %sum
 }
 
+; https://bugs.llvm.org/show_bug.cgi?id=34856
+; This would assert/crash because we didn't propagate the condition with the correct vector type.
+
+define <2 x i32> @PR34856(<2 x i32> %t0, <2 x i32> %t1) {
+; CHECK-LABEL: @PR34856(
+; CHECK-NEXT:    [[DIV1:%.*]] = udiv <2 x i32> %t1, <i32 -7, i32 -7>
+; CHECK-NEXT:    ret <2 x i32> [[DIV1]]
+;
+  %cmp = icmp eq <2 x i32> %t0, <i32 1, i32 1>
+  %zext = zext <2 x i1> %cmp to <2 x i32>
+  %neg = select <2 x i1> %cmp, <2 x i32> zeroinitializer, <2 x i32> <i32 -7, i32 -7>
+  %div1 = udiv <2 x i32> %t1, %neg
+  %use_cmp_again = add <2 x i32> %div1, %zext
+  ret <2 x i32> %use_cmp_again
+}
+