[LVI] Handle range attributes (#86413)

This adds handling of range attribute for return values of Call and
Invoke in getFromRangeMetadata and handling of argument with range
attribute in solveBlockValueNonLocal.
There is one additional check of the range metadata at line 1120 in
getValueFromSimpleICmpCondition that is not covered in this PR as after
#75311 there is no test that
cover that check any more and I have not been able to create a test that
trigger that code.

Author: andjo403

llvm/lib/Analysis/LazyValueInfo.cpp

@@ -588,10 +588,14 @@ LazyValueInfoImpl::getBlockValue(Value *Val, BasicBlock *BB,
 
 static ValueLatticeElement getFromRangeMetadata(Instruction *BBI) {
   switch (BBI->getOpcode()) {
-  default: break;
-  case Instruction::Load:
+  default:
+    break;
   case Instruction::Call:
   case Instruction::Invoke:
+    if (std::optional<ConstantRange> Range = cast<CallBase>(BBI)->getRange())
+      return ValueLatticeElement::getRange(*Range);
+    [[fallthrough]];
+  case Instruction::Load:
     if (MDNode *Ranges = BBI->getMetadata(LLVMContext::MD_range))
       if (isa<IntegerType>(BBI->getType())) {
         return ValueLatticeElement::getRange(
@@ -706,10 +710,11 @@ std::optional<ValueLatticeElement>
 LazyValueInfoImpl::solveBlockValueNonLocal(Value *Val, BasicBlock *BB) {
   ValueLatticeElement Result;  // Start Undefined.
 
-  // If this is the entry block, we must be asking about an argument.  The
-  // value is overdefined.
+  // If this is the entry block, we must be asking about an argument.
   if (BB->isEntryBlock()) {
     assert(isa<Argument>(Val) && "Unknown live-in to the entry block");
+    if (std::optional<ConstantRange> Range = cast<Argument>(Val)->getRange())
+      return ValueLatticeElement::getRange(*Range);
     return ValueLatticeElement::getOverdefined();
   }
 

llvm/test/Transforms/CorrelatedValuePropagation/range.ll

@@ -102,9 +102,9 @@ if.end8:
 define i32 @test4(i32 %c) nounwind {
 ; CHECK-LABEL: @test4(
 ; CHECK-NEXT:    switch i32 [[C:%.*]], label [[SW_DEFAULT:%.*]] [
-; CHECK-NEXT:    i32 1, label [[SW_BB:%.*]]
-; CHECK-NEXT:    i32 2, label [[SW_BB]]
-; CHECK-NEXT:    i32 4, label [[SW_BB]]
+; CHECK-NEXT:      i32 1, label [[SW_BB:%.*]]
+; CHECK-NEXT:      i32 2, label [[SW_BB]]
+; CHECK-NEXT:      i32 4, label [[SW_BB]]
 ; CHECK-NEXT:    ]
 ; CHECK:       sw.bb:
 ; CHECK-NEXT:    br i1 true, label [[IF_THEN:%.*]], label [[IF_END:%.*]]
@@ -207,8 +207,8 @@ define i1 @test7(i32 %c) nounwind {
 ; CHECK-LABEL: @test7(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    switch i32 [[C:%.*]], label [[SW_DEFAULT:%.*]] [
-; CHECK-NEXT:    i32 6, label [[SW_BB:%.*]]
-; CHECK-NEXT:    i32 7, label [[SW_BB]]
+; CHECK-NEXT:      i32 6, label [[SW_BB:%.*]]
+; CHECK-NEXT:      i32 7, label [[SW_BB]]
 ; CHECK-NEXT:    ]
 ; CHECK:       sw.bb:
 ; CHECK-NEXT:    ret i1 true
@@ -790,8 +790,8 @@ define i32 @test18(i8 %a) {
 ; CHECK-NEXT:    br label [[DISPATCH:%.*]]
 ; CHECK:       dispatch:
 ; CHECK-NEXT:    switch i8 [[A]], label [[DISPATCH]] [
-; CHECK-NEXT:    i8 93, label [[TARGET93:%.*]]
-; CHECK-NEXT:    i8 -111, label [[DISPATCH]]
+; CHECK-NEXT:      i8 93, label [[TARGET93:%.*]]
+; CHECK-NEXT:      i8 -111, label [[DISPATCH]]
 ; CHECK-NEXT:    ]
 ; CHECK:       target93:
 ; CHECK-NEXT:    ret i32 93
@@ -817,8 +817,8 @@ define i8 @test19(i8 %a) {
 ; CHECK-NEXT:    br label [[DISPATCH:%.*]]
 ; CHECK:       dispatch:
 ; CHECK-NEXT:    switch i8 [[A]], label [[DISPATCH]] [
-; CHECK-NEXT:    i8 93, label [[TARGET93:%.*]]
-; CHECK-NEXT:    i8 -111, label [[DISPATCH]]
+; CHECK-NEXT:      i8 93, label [[TARGET93:%.*]]
+; CHECK-NEXT:      i8 -111, label [[DISPATCH]]
 ; CHECK-NEXT:    ]
 ; CHECK:       target93:
 ; CHECK-NEXT:    ret i8 96
@@ -846,8 +846,8 @@ define i1 @test20(i64 %a) {
 ; CHECK-NEXT:    br label [[DISPATCH:%.*]]
 ; CHECK:       dispatch:
 ; CHECK-NEXT:    switch i64 [[A]], label [[DEFAULT:%.*]] [
-; CHECK-NEXT:    i64 0, label [[EXIT2:%.*]]
-; CHECK-NEXT:    i64 -2147483647, label [[EXIT2]]
+; CHECK-NEXT:      i64 0, label [[EXIT2:%.*]]
+; CHECK-NEXT:      i64 -2147483647, label [[EXIT2]]
 ; CHECK-NEXT:    ]
 ; CHECK:       default:
 ; CHECK-NEXT:    [[C:%.*]] = icmp eq i64 [[B]], 0
@@ -1123,6 +1123,70 @@ else:
   ret i1 true
 }
 
+define i1 @icmp_eq_range_attr(i8 range(i8 1, 0) %i) {
+; CHECK-LABEL: @icmp_eq_range_attr(
+; CHECK-NEXT:    ret i1 false
+;
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
+define i1 @neg_icmp_eq_range_attr(i8 range(i8 -1, 1) %i) {
+; CHECK-LABEL: @neg_icmp_eq_range_attr(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[I:%.*]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
+declare range(i8 1, 0) i8 @returns_non_zero_range_helper()
+declare range(i8 -1, 1) i8 @returns_contain_zero_range_helper()
+
+define i1 @icmp_eq_range_return() {
+; CHECK-LABEL: @icmp_eq_range_return(
+; CHECK-NEXT:    [[I:%.*]] = call i8 @returns_non_zero_range_helper()
+; CHECK-NEXT:    ret i1 false
+;
+  %i = call i8 @returns_non_zero_range_helper()
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
+define i1 @neg_icmp_eq_range_return() {
+; CHECK-LABEL: @neg_icmp_eq_range_return(
+; CHECK-NEXT:    [[I:%.*]] = call i8 @returns_contain_zero_range_helper()
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[I]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %i = call i8 @returns_contain_zero_range_helper()
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
+declare i8 @returns_i8_helper()
+
+define i1 @icmp_eq_range_call() {
+; CHECK-LABEL: @icmp_eq_range_call(
+; CHECK-NEXT:    [[I:%.*]] = call range(i8 1, 0) i8 @returns_i8_helper()
+; CHECK-NEXT:    ret i1 false
+;
+  %i = call range(i8 1, 0) i8 @returns_i8_helper()
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
+define i1 @neg_icmp_eq_range_call() {
+; CHECK-LABEL: @neg_icmp_eq_range_call(
+; CHECK-NEXT:    [[I:%.*]] = call range(i8 0, 11) i8 @returns_i8_helper()
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[I]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %i = call range(i8 0, 11) i8 @returns_i8_helper()
+  %cmp = icmp eq i8 %i, 0
+  ret i1 %cmp
+}
+
 declare i16 @llvm.ctlz.i16(i16, i1)
 declare i16 @llvm.cttz.i16(i16, i1)
 declare i16 @llvm.ctpop.i16(i16)