Take range metadata into account for conditions like this:
%length = load i32, i32* %length_ptr, !range !{i32 0, i32
2147483647}
%cmp = icmp ult i32 %a, %length
This is a common pattern for range checks where the length of the array is dynamically loaded.
Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D23267
llvm-svn: 278496
/*isFullSet=*/true);
if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS))
RHSRange = ConstantRange(CI->getValue());
+ else if (Instruction *I = dyn_cast<Instruction>(RHS))
+ if (auto *Ranges = I->getMetadata(LLVMContext::MD_range))
+ RHSRange = getConstantRangeFromMetadata(*Ranges);
// If we're interested in the false dest, invert the condition
CmpInst::Predicate Pred =
exit:
ret void
}
+
+@limit = external global i32
+; CHECK-LABEL: @test11(
+define i32 @test11(i32* %p, i32 %i) {
+ %limit = load i32, i32* %p, !range !{i32 0, i32 2147483647}
+ %within.1 = icmp ugt i32 %limit, %i
+ %i.plus.7 = add i32 %i, 7
+ %within.2 = icmp ugt i32 %limit, %i.plus.7
+ %within = and i1 %within.1, %within.2
+ br i1 %within, label %then, label %else
+
+then:
+; CHECK: %i.plus.6 = add nuw nsw i32 %i, 6
+ %i.plus.6 = add i32 %i, 6
+ ret i32 %i.plus.6
+
+else:
+ ret i32 0
+}
else:
ret i1 false
}
+
+@limit = external global i32
+define i1 @test15(i32 %a) {
+; CHECK-LABEL: @test15(
+; CHECK: then:
+; CHECK-NEXT: ret i1 false
+ %limit = load i32, i32* @limit, !range !{i32 0, i32 256}
+ %cmp = icmp ult i32 %a, %limit
+ br i1 %cmp, label %then, label %else
+
+then:
+ %result = icmp eq i32 %a, 255
+ ret i1 %result
+
+else:
+ ret i1 false
+}