[llvm] [ADT] Add implementations for avgFloor and avgCeil to APInt (PR #84431)
Atousa Duprat via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 12 22:20:18 PDT 2024
https://github.com/Atousa updated https://github.com/llvm/llvm-project/pull/84431
>From 6c42041bea25268ceb9b5866047d2342c0960467 Mon Sep 17 00:00:00 2001
From: Atousa Duprat <atousa.p at gmail.com>
Date: Thu, 7 Mar 2024 19:22:51 -0800
Subject: [PATCH] [ADT] Add implementations for avgFloor and avgCeil to APInt
Supports both signed and unsigned expansions.
SelectionDAG now calls the APInt implementation of these functions.
---
llvm/include/llvm/ADT/APInt.h | 12 +++
.../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 32 ++-----
llvm/lib/Support/APInt.cpp | 36 ++++++++
llvm/unittests/ADT/APIntTest.cpp | 86 +++++++++++++++++++
4 files changed, 142 insertions(+), 24 deletions(-)
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index 1fc3c7b2236a17..3a58fff3be1d4c 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -2193,6 +2193,18 @@ inline const APInt absdiff(const APInt &A, const APInt &B) {
return A.uge(B) ? (A - B) : (B - A);
}
+/// Compute the floor of the signed average of C1 and C2
+APInt avgFloorS(const APInt &C1, const APInt &C2);
+
+/// Compute the floor of the unsigned average of C1 and C2
+APInt avgFloorU(const APInt &C1, const APInt &C2);
+
+/// Compute the ceil of the signed average of C1 and C2
+APInt avgCeilS(const APInt &C1, const APInt &C2);
+
+/// Compute the ceil of the unsigned average of C1 and C2
+APInt avgCeilU(const APInt &C1, const APInt &C2);
+
/// Compute GCD of two unsigned APInt values.
///
/// This function returns the greatest common divisor of the two APInt values
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f7ace79e8c51d4..a844a00be16291 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6021,30 +6021,14 @@ static std::optional<APInt> FoldValue(unsigned Opcode, const APInt &C1,
APInt C2Ext = C2.zext(FullWidth);
return (C1Ext * C2Ext).extractBits(C1.getBitWidth(), C1.getBitWidth());
}
- case ISD::AVGFLOORS: {
- unsigned FullWidth = C1.getBitWidth() + 1;
- APInt C1Ext = C1.sext(FullWidth);
- APInt C2Ext = C2.sext(FullWidth);
- return (C1Ext + C2Ext).extractBits(C1.getBitWidth(), 1);
- }
- case ISD::AVGFLOORU: {
- unsigned FullWidth = C1.getBitWidth() + 1;
- APInt C1Ext = C1.zext(FullWidth);
- APInt C2Ext = C2.zext(FullWidth);
- return (C1Ext + C2Ext).extractBits(C1.getBitWidth(), 1);
- }
- case ISD::AVGCEILS: {
- unsigned FullWidth = C1.getBitWidth() + 1;
- APInt C1Ext = C1.sext(FullWidth);
- APInt C2Ext = C2.sext(FullWidth);
- return (C1Ext + C2Ext + 1).extractBits(C1.getBitWidth(), 1);
- }
- case ISD::AVGCEILU: {
- unsigned FullWidth = C1.getBitWidth() + 1;
- APInt C1Ext = C1.zext(FullWidth);
- APInt C2Ext = C2.zext(FullWidth);
- return (C1Ext + C2Ext + 1).extractBits(C1.getBitWidth(), 1);
- }
+ case ISD::AVGFLOORS:
+ return APIntOps::avgFloorS(C1, C2);
+ case ISD::AVGFLOORU:
+ return APIntOps::avgFloorU(C1, C2);
+ case ISD::AVGCEILS:
+ return APIntOps::avgCeilS(C1, C2);
+ case ISD::AVGCEILU:
+ return APIntOps::avgCeilU(C1, C2);
case ISD::ABDS:
return APIntOps::smax(C1, C2) - APIntOps::smin(C1, C2);
case ISD::ABDU:
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index e686b976523302..37b64a1755cf1f 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -3094,3 +3094,39 @@ void llvm::LoadIntFromMemory(APInt &IntVal, const uint8_t *Src,
memcpy(Dst + sizeof(uint64_t) - LoadBytes, Src, LoadBytes);
}
}
+
+APInt APIntOps::avgFloorS(const APInt &C1, const APInt &C2) {
+ // Return floor((C1 + C2)/2)
+ assert(C1.getBitWidth() == C2.getBitWidth());
+ unsigned FullWidth = C1.getBitWidth() + 1;
+ APInt C1Ext = C1.sext(FullWidth);
+ APInt C2Ext = C2.sext(FullWidth);
+ return (C1Ext + C2Ext).extractBits(C1.getBitWidth(), 1);
+}
+
+APInt APIntOps::avgFloorU(const APInt &C1, const APInt &C2) {
+ // Return floor((C1 + C2)/2)
+ assert(C1.getBitWidth() == C2.getBitWidth());
+ unsigned FullWidth = C1.getBitWidth() + 1;
+ APInt C1Ext = C1.zext(FullWidth);
+ APInt C2Ext = C2.zext(FullWidth);
+ return (C1Ext + C2Ext).extractBits(C1.getBitWidth(), 1);
+}
+
+APInt APIntOps::avgCeilS(const APInt &C1, const APInt &C2) {
+ // Return ceil((C1 + C2)/2)
+ assert(C1.getBitWidth() == C2.getBitWidth());
+ unsigned FullWidth = C1.getBitWidth() + 1;
+ APInt C1Ext = C1.sext(FullWidth);
+ APInt C2Ext = C2.sext(FullWidth);
+ return (C1Ext + C2Ext + 1).extractBits(C1.getBitWidth(), 1);
+}
+
+APInt APIntOps::avgCeilU(const APInt &C1, const APInt &C2) {
+ // Return ceil((C1 + C2)/2)
+ assert(C1.getBitWidth() == C2.getBitWidth());
+ unsigned FullWidth = C1.getBitWidth() + 1;
+ APInt C1Ext = C1.zext(FullWidth);
+ APInt C2Ext = C2.zext(FullWidth);
+ return (C1Ext + C2Ext + 1).extractBits(C1.getBitWidth(), 1);
+}
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 24324822356bf6..3e49b5876e0b83 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -14,6 +14,7 @@
#include "llvm/Support/Alignment.h"
#include "gtest/gtest.h"
#include <array>
+#include <climits>
#include <optional>
using namespace llvm;
@@ -2877,6 +2878,91 @@ TEST(APIntTest, RoundingSDiv) {
}
}
+TEST(APIntTest, Average) {
+ APInt A0(32, 0);
+ APInt A2(32, 2);
+ APInt A100(32, 100);
+ APInt A101(32, 101);
+ APInt A200(32, 200, false);
+ APInt ApUMax(32, UINT_MAX, false);
+
+ EXPECT_EQ(APInt(32, 150), APIntOps::avgFloorU(A100, A200));
+ EXPECT_EQ(APIntOps::RoundingUDiv(A100 + A200, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorU(A100, A200));
+ EXPECT_EQ(APIntOps::RoundingUDiv(A100 + A200, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilU(A100, A200));
+ EXPECT_EQ(APIntOps::RoundingUDiv(A100 + A101, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorU(A100, A101));
+ EXPECT_EQ(APIntOps::RoundingUDiv(A100 + A101, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilU(A100, A101));
+ EXPECT_EQ(A0, APIntOps::avgFloorU(A0, A0));
+ EXPECT_EQ(A0, APIntOps::avgCeilU(A0, A0));
+ EXPECT_EQ(ApUMax, APIntOps::avgFloorU(ApUMax, ApUMax));
+ EXPECT_EQ(ApUMax, APIntOps::avgCeilU(ApUMax, ApUMax));
+ EXPECT_EQ(APIntOps::RoundingUDiv(ApUMax, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorU(A0, ApUMax));
+ EXPECT_EQ(APIntOps::RoundingUDiv(ApUMax, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilU(A0, ApUMax));
+
+ APInt Ap100(32, +100);
+ APInt Ap101(32, +101);
+ APInt Ap200(32, +200);
+ APInt Am1(32, -1);
+ APInt Am100(32, -100);
+ APInt Am101(32, -101);
+ APInt Am200(32, -200);
+ APInt AmSMin(32, INT_MIN);
+ APInt ApSMax(32, INT_MAX);
+
+ EXPECT_EQ(APInt(32, +150), APIntOps::avgFloorS(Ap100, Ap200));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Ap100 + Ap200, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(Ap100, Ap200));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Ap100 + Ap200, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(Ap100, Ap200));
+
+ EXPECT_EQ(APInt(32, -150), APIntOps::avgFloorS(Am100, Am200));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Am100 + Am200, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(Am100, Am200));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Am100 + Am200, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(Am100, Am200));
+
+ EXPECT_EQ(APInt(32, +100), APIntOps::avgFloorS(Ap100, Ap101));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Ap100 + Ap101, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(Ap100, Ap101));
+ EXPECT_EQ(APInt(32, +101), APIntOps::avgCeilS(Ap100, Ap101));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Ap100 + Ap101, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(Ap100, Ap101));
+
+ EXPECT_EQ(APInt(32, -101), APIntOps::avgFloorS(Am100, Am101));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Am100 + Am101, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(Am100, Am101));
+ EXPECT_EQ(APInt(32, -100), APIntOps::avgCeilS(Am100, Am101));
+ EXPECT_EQ(APIntOps::RoundingSDiv(Am100 + Am101, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(Am100, Am101));
+
+ EXPECT_EQ(AmSMin, APIntOps::avgFloorS(AmSMin, AmSMin));
+ EXPECT_EQ(AmSMin, APIntOps::avgCeilS(AmSMin, AmSMin));
+
+ EXPECT_EQ(APIntOps::RoundingSDiv(AmSMin, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(A0, AmSMin));
+ EXPECT_EQ(APIntOps::RoundingSDiv(AmSMin, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(A0, AmSMin));
+
+ EXPECT_EQ(A0, APIntOps::avgFloorS(A0, A0));
+ EXPECT_EQ(A0, APIntOps::avgCeilS(A0, A0));
+
+ EXPECT_EQ(Am1, APIntOps::avgFloorS(AmSMin, ApSMax));
+ EXPECT_EQ(A0, APIntOps::avgCeilS(AmSMin, ApSMax));
+
+ EXPECT_EQ(APIntOps::RoundingSDiv(ApSMax, A2, APInt::Rounding::DOWN),
+ APIntOps::avgFloorS(A0, ApSMax));
+ EXPECT_EQ(APIntOps::RoundingSDiv(ApSMax, A2, APInt::Rounding::UP),
+ APIntOps::avgCeilS(A0, ApSMax));
+
+ EXPECT_EQ(ApSMax, APIntOps::avgFloorS(ApSMax, ApSMax));
+ EXPECT_EQ(ApSMax, APIntOps::avgCeilS(ApSMax, ApSMax));
+}
+
TEST(APIntTest, umul_ov) {
const std::pair<uint64_t, uint64_t> Overflows[] = {
{0x8000000000000000, 2},
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