Added some checks to preserve the logic of existing code exactly.

Added more tests.

Author: mgudim

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -2969,10 +2969,11 @@ Instruction *InstCombinerImpl::foldICmpAddLikeConstant(ICmpInst &Cmp,
   // If the add does not wrap, we can always adjust the compare by subtracting
   // the constants. Equality comparisons are handled elsewhere. SGE/SLE/UGE/ULE
   // are canonicalized to SGT/SLT/UGT/ULT.
-  if (AddLike->getOpcode() == Instruction::Or ||
-      (AddLike->hasNoSignedWrap() &&
+  if (((AddLike->getOpcode() == Instruction::Or ||
+        AddLike->hasNoSignedWrap()) &&
        (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLT)) ||
-      (AddLike->hasNoUnsignedWrap() &&
+      ((AddLike->getOpcode() == Instruction::Or ||
+        AddLike->hasNoUnsignedWrap()) &&
        (Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_ULT))) {
     bool Overflow;
     APInt NewC =

llvm/test/Transforms/InstCombine/icmp.ll

@@ -5138,12 +5138,62 @@ entry:
   ret i1 %cmp
 }
 
-define i1 @icmp_disjoint_or(i32 %x) {
-; CHECK-LABEL: @icmp_disjoint_or(
+define i1 @icmp_disjoint_or_sgt(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_sgt(
 ; CHECK-NEXT:    [[C:%.*]] = icmp sgt i32 [[X:%.*]], 35
 ; CHECK-NEXT:    ret i1 [[C]]
 ;
   %or_ = or disjoint i32 %x, 6
   %C = icmp sgt i32 %or_, 41
   ret i1 %C
 }
+
+define i1 @icmp_disjoint_or_slt(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_slt(
+; CHECK-NEXT:    [[C:%.*]] = icmp slt i32 [[X:%.*]], 35
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %or_ = or disjoint i32 %x, 6
+  %C = icmp slt i32 %or_, 41
+  ret i1 %C
+}
+
+define i1 @icmp_disjoint_or_ult(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_ult(
+; CHECK-NEXT:    [[C:%.*]] = icmp ult i32 [[X:%.*]], 35
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %or_ = or disjoint i32 %x, 6
+  %C = icmp ult i32 %or_, 41
+  ret i1 %C
+}
+
+define i1 @icmp_disjoint_or_ugt(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_ugt(
+; CHECK-NEXT:    [[C:%.*]] = icmp ugt i32 [[X:%.*]], 35
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %or_ = or disjoint i32 %x, 6
+  %C = icmp ugt i32 %or_, 41
+  ret i1 %C
+}
+
+define i1 @icmp_disjoint_or_eq(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_eq(
+; CHECK-NEXT:    [[C:%.*]] = icmp eq i32 [[X:%.*]], 0
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %or_ = or disjoint i32 %x, 5
+  %C = icmp eq i32 %or_, 5
+  ret i1 %C
+}
+
+define i1 @icmp_disjoint_or_be(i32 %x) {
+; CHECK-LABEL: @icmp_disjoint_or_be(
+; CHECK-NEXT:    [[C:%.*]] = icmp ne i32 [[X:%.*]], 0
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %or_ = or disjoint i32 %x, 5
+  %C = icmp ne i32 %or_, 5
+  ret i1 %C
+}