[llvm] [ConstantRange] Handle `Intrinsic::ctpop` (PR #68310)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Sun Nov 5 08:41:55 PST 2023
https://github.com/dtcxzyw updated https://github.com/llvm/llvm-project/pull/68310
>From a54f0145f909603c4cd3af8df6ab54eab0f9c545 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Thu, 5 Oct 2023 21:48:04 +0800
Subject: [PATCH 1/3] [ConstantRange] Handle `Intrinsic::ctpop`
---
llvm/include/llvm/IR/ConstantRange.h | 3 ++
llvm/lib/IR/ConstantRange.cpp | 49 +++++++++++++++++++
.../CorrelatedValuePropagation/range.ll | 3 +-
llvm/unittests/IR/ConstantRangeTest.cpp | 6 +++
4 files changed, 59 insertions(+), 2 deletions(-)
diff --git a/llvm/include/llvm/IR/ConstantRange.h b/llvm/include/llvm/IR/ConstantRange.h
index ca36732e4e2e8c2..017f1f36d8a663e 100644
--- a/llvm/include/llvm/IR/ConstantRange.h
+++ b/llvm/include/llvm/IR/ConstantRange.h
@@ -530,6 +530,9 @@ class [[nodiscard]] ConstantRange {
/// ignoring a possible zero value contained in the input range.
ConstantRange ctlz(bool ZeroIsPoison = false) const;
+ /// Calculate ctpop range.
+ ConstantRange ctpop() const;
+
/// Represents whether an operation on the given constant range is known to
/// always or never overflow.
enum class OverflowResult {
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 3d71b20f7e853e0..f00fb1f1b9f36cc 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -949,6 +949,7 @@ bool ConstantRange::isIntrinsicSupported(Intrinsic::ID IntrinsicID) {
case Intrinsic::smax:
case Intrinsic::abs:
case Intrinsic::ctlz:
+ case Intrinsic::ctpop:
return true;
default:
return false;
@@ -986,6 +987,8 @@ ConstantRange ConstantRange::intrinsic(Intrinsic::ID IntrinsicID,
assert(ZeroIsPoison->getBitWidth() == 1 && "Must be boolean");
return Ops[0].ctlz(ZeroIsPoison->getBoolValue());
}
+ case Intrinsic::ctpop:
+ return Ops[0].ctpop();
default:
assert(!isIntrinsicSupported(IntrinsicID) && "Shouldn't be supported");
llvm_unreachable("Unsupported intrinsic");
@@ -1736,6 +1739,52 @@ ConstantRange ConstantRange::ctlz(bool ZeroIsPoison) const {
APInt(getBitWidth(), getUnsignedMin().countl_zero() + 1));
}
+static ConstantRange getUnsignedPopCountRange(const APInt &Lower,
+ const APInt &Upper) {
+ assert(Lower.ule(Upper) && "Unexpected wrapped set.");
+ unsigned BitWidth = Lower.getBitWidth();
+ if (Lower == Upper)
+ return ConstantRange::getEmpty(BitWidth);
+ if (Lower + 1 == Upper)
+ return ConstantRange(APInt(BitWidth, Lower.popcount()));
+
+ APInt Max = Upper - 1;
+ // Calculate longest common prefix.
+ unsigned LCPLength = (Lower ^ Max).countl_zero();
+ unsigned LCPPopCount = Lower.getHiBits(LCPLength).popcount();
+ // If Lower is {LCP, 000...}, the minimum is the popcount of LCP.
+ // Otherwise, the minimum is the popcount of LCP + 1.
+ unsigned MinBits =
+ LCPPopCount + (Lower.countr_zero() < BitWidth - LCPLength ? 1 : 0);
+ // If Max is {LCP, 111...}, the maximum is the popcount of LCP + (BitWidth -
+ // length of LCP).
+ // Otherwise, the minimum is the popcount of LCP + (BitWidth -
+ // length of LCP - 1).
+ unsigned MaxBits = LCPPopCount + (BitWidth - LCPLength) +
+ (Max.countr_one() >= BitWidth - LCPLength ? 1 : 0);
+ return ConstantRange(APInt(BitWidth, MinBits), APInt(BitWidth, MaxBits));
+}
+
+ConstantRange ConstantRange::ctpop() const {
+ if (isEmptySet())
+ return getEmpty();
+
+ unsigned BitWidth = getBitWidth();
+ APInt Zero = APInt::getZero(BitWidth);
+ if (isFullSet()) {
+ return getNonEmpty(Zero, APInt(BitWidth, BitWidth + 1));
+ }
+ if (!isUpperWrapped()) {
+ return getUnsignedPopCountRange(getLower(), getUpper());
+ }
+ ConstantRange CR1 = ConstantRange(
+ APInt(BitWidth,
+ BitWidth - (getUnsignedMax() - getLower() + 1).logBase2()),
+ APInt(BitWidth, BitWidth + 1)); // [lower, intmax]
+ ConstantRange CR2 = getUnsignedPopCountRange(Zero, getUpper()); // [0, upper)
+ return CR1.unionWith(CR2);
+}
+
ConstantRange::OverflowResult ConstantRange::unsignedAddMayOverflow(
const ConstantRange &Other) const {
if (isEmptySet() || Other.isEmptySet())
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
index 5c10fdcd2b49217..cf85753e59c8083 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
@@ -1085,8 +1085,7 @@ define i1 @ctpop_fold(i16 %x) {
; CHECK-NEXT: br i1 [[CMP]], label [[IF:%.*]], label [[ELSE:%.*]]
; CHECK: if:
; CHECK-NEXT: [[CTPOP:%.*]] = call i16 @llvm.ctpop.i16(i16 [[X]])
-; CHECK-NEXT: [[RES:%.*]] = icmp ule i16 [[CTPOP]], 8
-; CHECK-NEXT: ret i1 [[RES]]
+; CHECK-NEXT: ret i1 true
; CHECK: else:
; CHECK-NEXT: ret i1 true
;
diff --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index 1cb358a26062ca5..12facfb22fb3c73 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -2438,6 +2438,12 @@ TEST_F(ConstantRangeTest, Ctlz) {
});
}
+TEST_F(ConstantRangeTest, Ctpop) {
+ TestUnaryOpExhaustive(
+ [](const ConstantRange &CR) { return CR.ctpop(); },
+ [](const APInt &N) { return APInt(N.getBitWidth(), N.popcount()); });
+}
+
TEST_F(ConstantRangeTest, castOps) {
ConstantRange A(APInt(16, 66), APInt(16, 128));
ConstantRange FpToI8 = A.castOp(Instruction::FPToSI, 8);
>From 77efe2e7f38df9edd84c536e9142eecc4362fad0 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Sat, 4 Nov 2023 21:55:38 +0800
Subject: [PATCH 2/3] fixup! [ConstantRange] Handle `Intrinsic::ctpop`
---
llvm/lib/IR/ConstantRange.cpp | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index f00fb1f1b9f36cc..97cccdd05b0619f 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -1741,10 +1741,10 @@ ConstantRange ConstantRange::ctlz(bool ZeroIsPoison) const {
static ConstantRange getUnsignedPopCountRange(const APInt &Lower,
const APInt &Upper) {
- assert(Lower.ule(Upper) && "Unexpected wrapped set.");
+ assert(!ConstantRange(Lower, Upper).isWrappedSet() &&
+ "Unexpected wrapped set.");
+ assert(Lower != Upper && "Unexpected empty set.");
unsigned BitWidth = Lower.getBitWidth();
- if (Lower == Upper)
- return ConstantRange::getEmpty(BitWidth);
if (Lower + 1 == Upper)
return ConstantRange(APInt(BitWidth, Lower.popcount()));
@@ -1760,9 +1760,9 @@ static ConstantRange getUnsignedPopCountRange(const APInt &Lower,
// length of LCP).
// Otherwise, the minimum is the popcount of LCP + (BitWidth -
// length of LCP - 1).
- unsigned MaxBits = LCPPopCount + (BitWidth - LCPLength) +
- (Max.countr_one() >= BitWidth - LCPLength ? 1 : 0);
- return ConstantRange(APInt(BitWidth, MinBits), APInt(BitWidth, MaxBits));
+ unsigned MaxBits = LCPPopCount + (BitWidth - LCPLength) -
+ (Max.countr_one() < BitWidth - LCPLength ? 1 : 0);
+ return ConstantRange(APInt(BitWidth, MinBits), APInt(BitWidth, MaxBits + 1));
}
ConstantRange ConstantRange::ctpop() const {
@@ -1771,17 +1771,17 @@ ConstantRange ConstantRange::ctpop() const {
unsigned BitWidth = getBitWidth();
APInt Zero = APInt::getZero(BitWidth);
- if (isFullSet()) {
+ if (isFullSet())
return getNonEmpty(Zero, APInt(BitWidth, BitWidth + 1));
- }
- if (!isUpperWrapped()) {
+ if (!isWrappedSet())
return getUnsignedPopCountRange(getLower(), getUpper());
- }
- ConstantRange CR1 = ConstantRange(
- APInt(BitWidth,
- BitWidth - (getUnsignedMax() - getLower() + 1).logBase2()),
- APInt(BitWidth, BitWidth + 1)); // [lower, intmax]
- ConstantRange CR2 = getUnsignedPopCountRange(Zero, getUpper()); // [0, upper)
+ // The range is wrapped. We decompose it into two ranges, [0, Upper) and
+ // [Lower, 0).
+ // Handle [Lower, 0) == [Lower, Max]
+ ConstantRange CR1 = ConstantRange(APInt(BitWidth, getLower().countl_one()),
+ APInt(BitWidth, BitWidth + 1));
+ // Handle [0, Upper)
+ ConstantRange CR2 = getUnsignedPopCountRange(Zero, getUpper());
return CR1.unionWith(CR2);
}
>From 898882c2b39ac56d6fa1fefe7e2689d3247627ee Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Mon, 6 Nov 2023 00:41:24 +0800
Subject: [PATCH 3/3] fixup! [ConstantRange] Handle `Intrinsic::ctpop`
Address comments.
---
llvm/lib/IR/ConstantRange.cpp | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 97cccdd05b0619f..af93b69a11c4dab 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -1774,14 +1774,14 @@ ConstantRange ConstantRange::ctpop() const {
if (isFullSet())
return getNonEmpty(Zero, APInt(BitWidth, BitWidth + 1));
if (!isWrappedSet())
- return getUnsignedPopCountRange(getLower(), getUpper());
+ return getUnsignedPopCountRange(Lower, Upper);
// The range is wrapped. We decompose it into two ranges, [0, Upper) and
// [Lower, 0).
// Handle [Lower, 0) == [Lower, Max]
- ConstantRange CR1 = ConstantRange(APInt(BitWidth, getLower().countl_one()),
+ ConstantRange CR1 = ConstantRange(APInt(BitWidth, Lower.countl_one()),
APInt(BitWidth, BitWidth + 1));
// Handle [0, Upper)
- ConstantRange CR2 = getUnsignedPopCountRange(Zero, getUpper());
+ ConstantRange CR2 = getUnsignedPopCountRange(Zero, Upper);
return CR1.unionWith(CR2);
}
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