return false;
}
+ case Instruction::ICmp:
+ // Comparing poison with any value yields poison. This is why, for
+ // instance, x s< (x +nsw 1) can be folded to true.
+ return true;
+
case Instruction::GetElementPtr:
// A GEP implicitly represents a sequence of additions, subtractions,
// truncations, sign extensions and multiplications. The multiplications
ret void
}
+define void @test-add-nuw-from-icmp(float* %input, i32 %offset,
+ i32 %numIterations) {
+; CHECK-LABEL: @test-add-nuw-from-icmp
+entry:
+ br label %loop
+loop:
+ %i = phi i32 [ %nexti, %loop ], [ 0, %entry ]
+
+; CHECK: %index32 =
+; CHECK: --> {%offset,+,1}<nuw>
+ %index32 = add nuw i32 %i, %offset
+ %cmp = icmp sgt i32 %index32, 0
+ %cmp.idx = sext i1 %cmp to i32
+
+ %ptr = getelementptr inbounds float, float* %input, i32 %cmp.idx
+ %nexti = add nuw i32 %i, 1
+ %f = load float, float* %ptr, align 4
+ %exitcond = icmp eq i32 %nexti, %numIterations
+ br i1 %exitcond, label %exit, label %loop
+
+exit:
+ ret void
+}
+
; With no load to trigger UB from poison, we cannot infer nsw.
define void @test-add-no-load(float* %input, i32 %offset, i32 %numIterations) {
; CHECK-LABEL: @test-add-no-load