[llvm] [InstCombine] Reduce range of ctpop for non zero argument (PR #100899)
Andreas Jonson via llvm-commits
llvm-commits at lists.llvm.org
Sat Jul 27 14:22:20 PDT 2024
https://github.com/andjo403 created https://github.com/llvm/llvm-project/pull/100899
None
>From dfabdd2bad713e7ae7468f33da0feea9e0885acb Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Sat, 27 Jul 2024 22:54:19 +0200
Subject: [PATCH 1/2] [InstCombine] Add pre-commit tests. NFC.
---
llvm/test/Transforms/InstCombine/ctpop.ll | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/llvm/test/Transforms/InstCombine/ctpop.ll b/llvm/test/Transforms/InstCombine/ctpop.ll
index 83700e72de080..3696ede71394d 100644
--- a/llvm/test/Transforms/InstCombine/ctpop.ll
+++ b/llvm/test/Transforms/InstCombine/ctpop.ll
@@ -169,8 +169,8 @@ define <2 x i32> @_parity_of_not_poison(<2 x i32> %x) {
define <2 x i32> @_parity_of_not_poison2(<2 x i32> %x) {
; CHECK-LABEL: @_parity_of_not_poison2(
-; CHECK-NEXT: [[CNT:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[X:%.*]])
-; CHECK-NEXT: [[R:%.*]] = and <2 x i32> [[CNT]], <i32 1, i32 poison>
+; CHECK-NEXT: [[TMP1:%.*]] = call range(i32 0, 33) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[X:%.*]])
+; CHECK-NEXT: [[R:%.*]] = and <2 x i32> [[TMP1]], <i32 1, i32 poison>
; CHECK-NEXT: ret <2 x i32> [[R]]
;
%neg = xor <2 x i32> %x, <i32 -1 ,i32 -1>
@@ -485,3 +485,12 @@ define i32 @select_ctpop_zero(i32 %x) {
%res = select i1 %cmp, i32 0, i32 %ctpop
ret i32 %res
}
+
+define i32 @ctpop_non_zero(i32 range(i32 1, 255) %x) {
+; CHECK-LABEL: @ctpop_non_zero(
+; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 9) i32 @llvm.ctpop.i32(i32 [[X:%.*]])
+; CHECK-NEXT: ret i32 [[CTPOP]]
+;
+ %ctpop = call i32 @llvm.ctpop.i32(i32 %x)
+ ret i32 %ctpop
+}
>From 1aeba2859495505c373109540e828d8a1a23892d Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Sat, 27 Jul 2024 23:19:59 +0200
Subject: [PATCH 2/2] [InstCombine] Reduce range of ctpop for non zero argument
---
llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 9 +++++++--
llvm/test/Transforms/InstCombine/ctpop-pow2.ll | 4 ++--
llvm/test/Transforms/InstCombine/ctpop.ll | 2 +-
llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll | 4 ++--
llvm/test/Transforms/InstCombine/ispow2.ll | 8 ++++----
5 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index f6c4b6e180937..52932f19512f3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -694,8 +694,13 @@ static Instruction *foldCtpop(IntrinsicInst &II, InstCombinerImpl &IC) {
// Add range attribute since known bits can't completely reflect what we know.
if (BitWidth != 1 && !II.hasRetAttr(Attribute::Range) &&
!II.getMetadata(LLVMContext::MD_range)) {
- ConstantRange Range(APInt(BitWidth, Known.countMinPopulation()),
- APInt(BitWidth, Known.countMaxPopulation() + 1));
+ unsigned KnownMinPop = Known.countMinPopulation();
+ unsigned Lower =
+ KnownMinPop ? KnownMinPop
+ : isKnownNonZero(
+ Op0, IC.getSimplifyQuery().getWithInstruction(&II));
+ unsigned Upper = Known.countMaxPopulation() + 1;
+ ConstantRange Range(APInt(BitWidth, Lower), APInt(BitWidth, Upper));
II.addRangeRetAttr(Range);
return &II;
}
diff --git a/llvm/test/Transforms/InstCombine/ctpop-pow2.ll b/llvm/test/Transforms/InstCombine/ctpop-pow2.ll
index 7facdaf7590d3..4ef1ed0ec4976 100644
--- a/llvm/test/Transforms/InstCombine/ctpop-pow2.ll
+++ b/llvm/test/Transforms/InstCombine/ctpop-pow2.ll
@@ -60,7 +60,7 @@ define i8 @ctpop_imin_plus1_lshr_nz(i8 %x) {
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]])
; CHECK-NEXT: [[V:%.*]] = lshr i8 -127, [[X]]
-; CHECK-NEXT: [[CNT:%.*]] = call range(i8 0, 9) i8 @llvm.ctpop.i8(i8 [[V]])
+; CHECK-NEXT: [[CNT:%.*]] = call range(i8 1, 9) i8 @llvm.ctpop.i8(i8 [[V]])
; CHECK-NEXT: ret i8 [[CNT]]
;
%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) {
; CHECK-LABEL: @ctpop_lshr_intmin_intmin_plus1_vec_nz(
; CHECK-NEXT: [[X1:%.*]] = or <2 x i32> [[X:%.*]], <i32 1, i32 1>
; CHECK-NEXT: [[SHR:%.*]] = lshr <2 x i32> <i32 -2147483648, i32 -2147483647>, [[X1]]
-; CHECK-NEXT: [[CNT:%.*]] = call range(i32 0, 17) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[SHR]])
+; CHECK-NEXT: [[CNT:%.*]] = call range(i32 1, 17) <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[SHR]])
; CHECK-NEXT: ret <2 x i32> [[CNT]]
;
%x1 = or <2 x i32> %x, <i32 1 ,i32 1>
diff --git a/llvm/test/Transforms/InstCombine/ctpop.ll b/llvm/test/Transforms/InstCombine/ctpop.ll
index 3696ede71394d..56ac2cad752a3 100644
--- a/llvm/test/Transforms/InstCombine/ctpop.ll
+++ b/llvm/test/Transforms/InstCombine/ctpop.ll
@@ -488,7 +488,7 @@ define i32 @select_ctpop_zero(i32 %x) {
define i32 @ctpop_non_zero(i32 range(i32 1, 255) %x) {
; CHECK-LABEL: @ctpop_non_zero(
-; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 9) i32 @llvm.ctpop.i32(i32 [[X:%.*]])
+; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 9) i32 @llvm.ctpop.i32(i32 [[X:%.*]])
; CHECK-NEXT: ret i32 [[CTPOP]]
;
%ctpop = call i32 @llvm.ctpop.i32(i32 %x)
diff --git a/llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll b/llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll
index e9ec6b415d462..618f5d641dc1a 100644
--- a/llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-ne-pow2.ll
@@ -306,7 +306,7 @@ define i32 @pow2_32_nonconst_assume(i32 %x, i32 %y) {
define i32 @pow2_32_gtnonconst_assume(i32 %x, i32 %y) {
; CHECK-LABEL: @pow2_32_gtnonconst_assume(
-; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[Y:%.*]])
+; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[Y:%.*]])
; CHECK-NEXT: [[YP2:%.*]] = icmp eq i32 [[CTPOP]], 1
; CHECK-NEXT: call void @llvm.assume(i1 [[YP2]])
; CHECK-NEXT: [[YGT:%.*]] = icmp ugt i32 [[Y]], [[X:%.*]]
@@ -513,7 +513,7 @@ define i32 @maybe_pow2_32_noncont(i32 %x, i32 %y) {
; CHECK-NEXT: [[YGT8:%.*]] = icmp ugt i32 [[Y:%.*]], 8
; CHECK-NEXT: br i1 [[YGT8]], label [[CONT1:%.*]], label [[CONT2:%.*]]
; CHECK: Cont1:
-; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[Y]])
+; CHECK-NEXT: [[CTPOP:%.*]] = call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[Y]])
; CHECK-NEXT: [[YP2:%.*]] = icmp eq i32 [[CTPOP]], 1
; CHECK-NEXT: call void @llvm.assume(i1 [[YP2]])
; CHECK-NEXT: br i1 true, label [[CONT2]], label [[FALSE:%.*]]
diff --git a/llvm/test/Transforms/InstCombine/ispow2.ll b/llvm/test/Transforms/InstCombine/ispow2.ll
index a143b1347ccee..3f2c31d05f3ed 100644
--- a/llvm/test/Transforms/InstCombine/ispow2.ll
+++ b/llvm/test/Transforms/InstCombine/ispow2.ll
@@ -197,7 +197,7 @@ define i1 @is_pow2_non_zero_ult_2(i32 %x) {
; CHECK-LABEL: @is_pow2_non_zero_ult_2(
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
-; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[T0]], 2
; CHECK-NEXT: ret i1 [[CMP]]
;
@@ -212,7 +212,7 @@ define i1 @is_pow2_non_zero_eq_1(i32 %x) {
; CHECK-LABEL: @is_pow2_non_zero_eq_1(
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
-; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[T0]], 1
; CHECK-NEXT: ret i1 [[CMP]]
;
@@ -227,7 +227,7 @@ define i1 @is_pow2_non_zero_ugt_1(i32 %x) {
; CHECK-LABEL: @is_pow2_non_zero_ugt_1(
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
-; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[T0]], 1
; CHECK-NEXT: ret i1 [[CMP]]
;
@@ -242,7 +242,7 @@ define i1 @is_pow2_non_zero_ne_1(i32 %x) {
; CHECK-LABEL: @is_pow2_non_zero_ne_1(
; CHECK-NEXT: [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
; CHECK-NEXT: call void @llvm.assume(i1 [[NOTZERO]])
-; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 [[X]])
+; CHECK-NEXT: [[T0:%.*]] = tail call range(i32 1, 33) i32 @llvm.ctpop.i32(i32 [[X]])
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[T0]], 1
; CHECK-NEXT: ret i1 [[CMP]]
;
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