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[InstCombine] Reduce range of ctpop for non zero argument
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5 files changed

+16
-11
lines changed

5 files changed

+16
-11
lines changed

‎llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

Lines changed: 7 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -694,8 +694,13 @@ static Instruction *foldCtpop(IntrinsicInst &II, InstCombinerImpl &IC) {
694694
// Add range attribute since known bits can't completely reflect what we know.
695695
if (BitWidth != 1 && !II.hasRetAttr(Attribute::Range) &&
696696
!II.getMetadata(LLVMContext::MD_range)) {
697-
ConstantRange Range(APInt(BitWidth, Known.countMinPopulation()),
698-
APInt(BitWidth, Known.countMaxPopulation() + 1));
697+
unsigned KnownMinPop = Known.countMinPopulation();
698+
unsigned Lower =
699+
KnownMinPop ? KnownMinPop
700+
: isKnownNonZero(
701+
Op0, IC.getSimplifyQuery().getWithInstruction(&II));
702+
unsigned Upper = Known.countMaxPopulation() + 1;
703+
ConstantRange Range(APInt(BitWidth, Lower), APInt(BitWidth, Upper));
699704
II.addRangeRetAttr(Range);
700705
return ⅈ
701706
}

‎llvm/test/Transforms/InstCombine/ctpop-pow2.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -60,7 +60,7 @@ define i8 @ctpop_imin_plus1_lshr_nz(i8 %x) {
6060
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], 0
6161
; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]])
6262
; CHECK-NEXT: [[V:%.*]] = lshr i8 -127, [[X]]
63-
; CHECK-NEXT: [[CNT:%.*]] = call range(i8 0, 9) i8 @llvm.ctpop.i8(i8 [[V]])
63+
; CHECK-NEXT: [[CNT:%.*]] = call range(i8 1, 9) i8 @llvm.ctpop.i8(i8 [[V]])
6464
; CHECK-NEXT: ret i8 [[CNT]]
6565
;
6666
%cmp = icmp ne i8 %x, 0
@@ -104,7 +104,7 @@ define <2 x i32> @ctpop_lshr_intmin_intmin_plus1_vec_nz(<2 x i32> %x) {
104104
; CHECK-LABEL: @ctpop_lshr_intmin_intmin_plus1_vec_nz(
105105
; CHECK-NEXT: [[X1:%.*]] = or <2 x i32> [[X:%.*]], <i32 1, i32 1>
106106
; CHECK-NEXT: [[SHR:%.*]] = lshr <2 x i32> <i32 -2147483648, i32 -2147483647>, [[X1]]
107-
; CHECK-NEXT: [[CNT:%.*]] = call range(i32 0, 17) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[SHR]])
107+
; CHECK-NEXT: [[CNT:%.*]] = call range(i32 1, 17) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[SHR]])
108108
; CHECK-NEXT: ret <2 x i32> [[CNT]]
109109
;
110110
%x1 = or <2 x i32> %x, <i32 1 ,i32 1>

‎llvm/test/Transforms/InstCombine/ctpop.ll

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -488,7 +488,7 @@ define i32 @select_ctpop_zero(i32 %x) {
488488

489489
define i32 @ctpop_non_zero(i32 range(i32 1, 255) %x) {
490490
; CHECK-LABEL: @ctpop_non_zero(
491-
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 9) i32 @llvm.ctpop.i32(i32 [[X:%.*]])
491+
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 9) i32 @llvm.ctpop.i32(i32 [[X:%.*]])
492492
; CHECK-NEXT: ret i32 [[CTPOP]]
493493
;
494494
%ctpop = call i32 @llvm.ctpop.i32(i32 %x)

‎llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -306,7 +306,7 @@ define i32 @pow2_32_nonconst_assume(i32 %x, i32 %y) {
306306

307307
define i32 @pow2_32_gtnonconst_assume(i32 %x, i32 %y) {
308308
; CHECK-LABEL: @pow2_32_gtnonconst_assume(
309-
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[Y:%.*]])
309+
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[Y:%.*]])
310310
; CHECK-NEXT: [[YP2:%.*]] = icmp eq i32 [[CTPOP]], 1
311311
; CHECK-NEXT: call void @llvm.assume(i1 [[YP2]])
312312
; CHECK-NEXT: [[YGT:%.*]] = icmp ugt i32 [[Y]], [[X:%.*]]
@@ -513,7 +513,7 @@ define i32 @maybe_pow2_32_noncont(i32 %x, i32 %y) {
513513
; CHECK-NEXT: [[YGT8:%.*]] = icmp ugt i32 [[Y:%.*]], 8
514514
; CHECK-NEXT: br i1 [[YGT8]], label [[CONT1:%.*]], label [[CONT2:%.*]]
515515
; CHECK: Cont1:
516-
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[Y]])
516+
; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[Y]])
517517
; CHECK-NEXT: [[YP2:%.*]] = icmp eq i32 [[CTPOP]], 1
518518
; CHECK-NEXT: call void @llvm.assume(i1 [[YP2]])
519519
; CHECK-NEXT: br i1 true, label [[CONT2]], label [[FALSE:%.*]]

‎llvm/test/Transforms/InstCombine/ispow2.ll

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -197,7 +197,7 @@ define i1 @is_pow2_non_zero_ult_2(i32 %x) {
197197
; CHECK-LABEL: @is_pow2_non_zero_ult_2(
198198
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
199199
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
200-
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
200+
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
201201
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[T0]], 2
202202
; CHECK-NEXT: ret i1 [[CMP]]
203203
;
@@ -212,7 +212,7 @@ define i1 @is_pow2_non_zero_eq_1(i32 %x) {
212212
; CHECK-LABEL: @is_pow2_non_zero_eq_1(
213213
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
214214
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
215-
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
215+
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
216216
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[T0]], 1
217217
; CHECK-NEXT: ret i1 [[CMP]]
218218
;
@@ -227,7 +227,7 @@ define i1 @is_pow2_non_zero_ugt_1(i32 %x) {
227227
; CHECK-LABEL: @is_pow2_non_zero_ugt_1(
228228
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
229229
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
230-
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
230+
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
231231
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[T0]], 1
232232
; CHECK-NEXT: ret i1 [[CMP]]
233233
;
@@ -242,7 +242,7 @@ define i1 @is_pow2_non_zero_ne_1(i32 %x) {
242242
; CHECK-LABEL: @is_pow2_non_zero_ne_1(
243243
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
244244
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
245-
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
245+
; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
246246
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[T0]], 1
247247
; CHECK-NEXT: ret i1 [[CMP]]
248248
;

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