An unsigned value converted to floating-point will always be greater than
a negative constant. Unfortunately InstCombine reversed the check so that
unsigned values were being optimized to always be greater than all positive
floating-point constants. <rdar://problem/
12029145>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161452
91177308-0d34-0410-b5e6-
96231b3b80d8
case ICmpInst::ICMP_UGE:
// (float)int >= -4.4 --> true
// (float)int >= 4.4 --> int > 4
- if (!RHS.isNegative())
+ if (RHS.isNegative())
return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
Pred = ICmpInst::ICMP_UGT;
break;
ret i1 %2
; CHECK: ret i1 false
}
+
+; Check that optimizing unsigned >= comparisons correctly distinguishes
+; positive and negative constants. <rdar://problem/12029145>
+define i1 @test7(i32 %val) {
+ %1 = uitofp i32 %val to double
+ %2 = fcmp oge double %1, 3.200000e+00
+ ret i1 %2
+; CHECK: icmp ugt i32 %val, 3
+}