return false;
}
+/// Does the 'Range' metadata (which must be a valid MD_range operand list)
+/// ensure that the value it's attached to is never Value? 'RangeType' is
+/// is the type of the value described by the range.
+static bool rangeMetadataExcludesValue(MDNode* Ranges,
+ const APInt& Value) {
+ const unsigned NumRanges = Ranges->getNumOperands() / 2;
+ assert(NumRanges >= 1);
+ for (unsigned i = 0; i < NumRanges; ++i) {
+ ConstantInt *Lower = cast<ConstantInt>(Ranges->getOperand(2*i + 0));
+ ConstantInt *Upper = cast<ConstantInt>(Ranges->getOperand(2*i + 1));
+ ConstantRange Range(Lower->getValue(), Upper->getValue());
+ if (Range.contains(Value))
+ return false;
+ }
+ return true;
+}
+
/// isKnownNonZero - Return true if the given value is known to be non-zero
/// when defined. For vectors return true if every element is known to be
/// non-zero when defined. Supports values with integer or pointer type and
return false;
}
+ if (Instruction* I = dyn_cast<Instruction>(V)) {
+ if (MDNode *Ranges = I->getMetadata(LLVMContext::MD_range)) {
+ // If the possible ranges don't contain zero, then the value is
+ // definitely non-zero.
+ if (IntegerType* Ty = dyn_cast<IntegerType>(V->getType())) {
+ const APInt ZeroValue(Ty->getBitWidth(), 0);
+ if (rangeMetadataExcludesValue(Ranges, ZeroValue))
+ return true;
+ }
+ }
+ }
+
// The remaining tests are all recursive, so bail out if we hit the limit.
if (Depth++ >= MaxDepth)
return false;
--- /dev/null
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; These should be InstSimplify checks, but most of the code
+; is currently only in InstCombine. TODO: move supporting code
+
+; Definitely out of range
+define i1 @test_nonzero(i32* nocapture readonly %arg) {
+; CHECK-LABEL:test_nonzero
+; CHECK: ret i1 true
+ %val = load i32* %arg, !range !0
+ %rval = icmp ne i32 %val, 0
+ ret i1 %rval
+}
+define i1 @test_nonzero2(i32* nocapture readonly %arg) {
+; CHECK-LABEL:test_nonzero2
+; CHECK: ret i1 false
+ %val = load i32* %arg, !range !0
+ %rval = icmp eq i32 %val, 0
+ ret i1 %rval
+}
+
+; Potentially in range
+define i1 @test_nonzero3(i32* nocapture readonly %arg) {
+; CHECK-LABEL: test_nonzero3
+; Check that this does not trigger - it wouldn't be legal
+; CHECK: icmp
+ %val = load i32* %arg, !range !1
+ %rval = icmp ne i32 %val, 0
+ ret i1 %rval
+}
+
+; Definitely in range
+define i1 @test_nonzero4(i8* nocapture readonly %arg) {
+; CHECK-LABEL: test_nonzero4
+; CHECK: ret i1 false
+ %val = load i8* %arg, !range !2
+ %rval = icmp ne i8 %val, 0
+ ret i1 %rval
+}
+
+define i1 @test_nonzero5(i8* nocapture readonly %arg) {
+; CHECK-LABEL: test_nonzero5
+; CHECK: ret i1 false
+ %val = load i8* %arg, !range !2
+ %rval = icmp ugt i8 %val, 0
+ ret i1 %rval
+}
+
+; Cheaper checks (most values in range meet requirements)
+define i1 @test_nonzero6(i8* %argw) {
+; CHECK-LABEL: test_nonzero6
+; CHECK: icmp ne i8 %val, 0
+ %val = load i8* %argw, !range !3
+ %rval = icmp sgt i8 %val, 0
+ ret i1 %rval
+}
+
+
+!0 = metadata !{i32 1, i32 6}
+!1 = metadata !{i32 0, i32 6}
+!2 = metadata !{i8 0, i8 1}
+!3 = metadata !{i8 0, i8 6}