[LVI] Don't push both binop operands at once

If one of the binop operands depends on the other, this may end
up evaluating them in the wrong order, producing sub-optimal
results.

Make sure that only one unevaluated operand gets pushed per
iteration.

Fixes #76705.

Author: nikic

llvm/lib/Analysis/LazyValueInfo.cpp

@@ -976,9 +976,11 @@ LazyValueInfoImpl::solveBlockValueBinaryOpImpl(
   // lets us pick up facts from expressions like "and i32 (call i32
   // @foo()), 32"
   std::optional<ConstantRange> LHSRes = getRangeFor(I->getOperand(0), I, BB);
+  if (!LHSRes)
+    return std::nullopt;
+
   std::optional<ConstantRange> RHSRes = getRangeFor(I->getOperand(1), I, BB);
-  if (!LHSRes || !RHSRes)
-    // More work to do before applying this transfer rule.
+  if (!RHSRes)
     return std::nullopt;
 
   const ConstantRange &LHSRange = *LHSRes;

llvm/test/Transforms/CorrelatedValuePropagation/basic.ll

@@ -1915,8 +1915,7 @@ define i1 @binop_eval_order(i32 %x) {
 ; CHECK-NEXT:    [[A:%.*]] = add nuw nsw i32 [[X:%.*]], 1
 ; CHECK-NEXT:    [[B:%.*]] = add nuw nsw i32 [[A]], 1
 ; CHECK-NEXT:    [[C:%.*]] = add nuw nsw i32 [[A]], [[B]]
-; CHECK-NEXT:    [[D:%.*]] = icmp ugt i32 [[C]], 2
-; CHECK-NEXT:    ret i1 [[D]]
+; CHECK-NEXT:    ret i1 true
 ;
   %a = add nuw nsw i32 %x, 1
   %b = add nuw nsw i32 %a, 1