if (Shr->isExact())
return new ICmpInst(Pred, X, ConstantInt::get(ShrTy, C << ShAmtVal));
+ if (C.isNullValue()) {
+ // == 0 is u< 1.
+ if (Pred == CmpInst::ICMP_EQ)
+ return new ICmpInst(CmpInst::ICMP_ULT, X,
+ ConstantInt::get(ShrTy, (C + 1).shl(ShAmtVal)));
+ else
+ return new ICmpInst(CmpInst::ICMP_UGT, X,
+ ConstantInt::get(ShrTy, (C + 1).shl(ShAmtVal) - 1));
+ }
+
if (Shr->hasOneUse()) {
// Canonicalize the shift into an 'and':
// icmp eq/ne (shr X, ShAmt), C --> icmp eq/ne (and X, HiMask), (C << ShAmt)
; CHECK-LABEL: @lshr_eq_0_multiuse(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 2
; CHECK-NEXT: call void @use(i8 [[S]])
-; CHECK-NEXT: [[C:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT: [[C:%.*]] = icmp ult i8 [[X]], 4
; CHECK-NEXT: ret i1 [[C]]
;
%s = lshr i8 %x, 2
; CHECK-LABEL: @lshr_ne_0_multiuse(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 2
; CHECK-NEXT: call void @use(i8 [[S]])
-; CHECK-NEXT: [[C:%.*]] = icmp ne i8 [[S]], 0
+; CHECK-NEXT: [[C:%.*]] = icmp ugt i8 [[X]], 3
; CHECK-NEXT: ret i1 [[C]]
;
%s = lshr i8 %x, 2
; CHECK-LABEL: @ashr_eq_0_multiuse(
; CHECK-NEXT: [[S:%.*]] = ashr i8 [[X:%.*]], 2
; CHECK-NEXT: call void @use(i8 [[S]])
-; CHECK-NEXT: [[C:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT: [[C:%.*]] = icmp ult i8 [[X]], 4
; CHECK-NEXT: ret i1 [[C]]
;
%s = ashr i8 %x, 2
; CHECK-LABEL: @ashr_ne_0_multiuse(
; CHECK-NEXT: [[S:%.*]] = ashr i8 [[X:%.*]], 2
; CHECK-NEXT: call void @use(i8 [[S]])
-; CHECK-NEXT: [[C:%.*]] = icmp ne i8 [[S]], 0
+; CHECK-NEXT: [[C:%.*]] = icmp ugt i8 [[X]], 3
; CHECK-NEXT: ret i1 [[C]]
;
%s = ashr i8 %x, 2
; RUN: opt -instcombine -S < %s | FileCheck %s
; Test that presence of range does not cause unprofitable transforms with bit
-; arithmetics, and instcombine behaves exactly the same as without the range.
+; arithmetics.
define i1 @without_range(i32* %A) {
; CHECK-LABEL: @without_range(
define i1 @with_range(i32* %A) {
; CHECK-LABEL: @with_range(
-; CHECK-NEXT: [[A_VAL:%.*]] = load i32, i32* [[A:%.*]], align 8, !range !0
-; CHECK-NEXT: [[B_MASK:%.*]] = and i32 [[A_VAL]], 2147483646
-; CHECK-NEXT: [[C:%.*]] = icmp eq i32 [[B_MASK]], 0
+; CHECK-NEXT: [[A_VAL:%.*]] = load i32, i32* [[A:%.*]], align 8, !range [[RNG0:![0-9]+]]
+; CHECK-NEXT: [[C:%.*]] = icmp ult i32 [[A_VAL]], 2
; CHECK-NEXT: ret i1 [[C]]
;
%A.val = load i32, i32* %A, align 8, !range !0
; CHECK-NEXT: [[I_02:%.*]] = phi i32 [ [[INC:%.*]], [[WHILE_BODY]] ], [ 0, [[WHILE_BODY_PREHEADER]] ]
; CHECK-NEXT: [[TMP1]] = lshr i32 [[N_ADDR_03]], 1
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[I_02]], 1
-; CHECK-NEXT: [[TOBOOL_NOT:%.*]] = icmp eq i32 [[TMP1]], 0
+; CHECK-NEXT: [[TOBOOL_NOT:%.*]] = icmp ult i32 [[N_ADDR_03]], 2
; CHECK-NEXT: br i1 [[TOBOOL_NOT]], label [[WHILE_END]], label [[WHILE_BODY]]
; CHECK: while.end:
; CHECK-NEXT: [[I_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC]], [[WHILE_BODY]] ]