[llvm] [ADT][APInt] add sfloordiv_ov APInt's member function (PR #84720)
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Thu Mar 14 06:44:46 PDT 2024
https://github.com/lipracer updated https://github.com/llvm/llvm-project/pull/84720
>From 0db9531587eb1ea67c1c8886d1550ae1563a2073 Mon Sep 17 00:00:00 2001
From: lipracer <lipracer at gmail.com>
Date: Mon, 11 Mar 2024 13:10:43 +0800
Subject: [PATCH 1/4] [APInt] add sfloordiv_ov APInt's member function for mlir
fold to avoid too many overflow state check
---
llvm/include/llvm/ADT/APInt.h | 1 +
llvm/lib/Support/APInt.cpp | 8 +++++++
llvm/unittests/ADT/APIntTest.cpp | 38 ++++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+)
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index b10e2107b794a3..b91aaa688013a9 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -996,6 +996,7 @@ class [[nodiscard]] APInt {
APInt sshl_ov(unsigned Amt, bool &Overflow) const;
APInt ushl_ov(const APInt &Amt, bool &Overflow) const;
APInt ushl_ov(unsigned Amt, bool &Overflow) const;
+ APInt sfloordiv_ov(const APInt &RHS, bool &Overflow) const;
// Operations that saturate
APInt sadd_sat(const APInt &RHS) const;
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 7053f3b87682f8..8fad85b2d0bccb 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -2022,6 +2022,14 @@ APInt APInt::ushl_ov(unsigned ShAmt, bool &Overflow) const {
return *this << ShAmt;
}
+APInt APInt::sfloordiv_ov(const APInt &RHS, bool &Overflow) const {
+ auto quotient = sdiv_ov(RHS, Overflow);
+ if ((quotient * RHS != *this) && (isNegative() != RHS.isNegative()))
+ return quotient - 1;
+ else
+ return quotient;
+}
+
APInt APInt::sadd_sat(const APInt &RHS) const {
bool Overflow;
APInt Res = sadd_ov(RHS, Overflow);
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 400313a6234677..749dd98efd260c 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -15,6 +15,7 @@
#include "gtest/gtest.h"
#include <array>
#include <climits>
+#include <limits>
#include <optional>
using namespace llvm;
@@ -3048,6 +3049,43 @@ TEST(APIntTest, smul_ov) {
}
}
+TEST(APIntTest, sfloordiv_ov) {
+ // test negative quotient
+ {
+ APInt divisor(32, -3, true);
+ APInt dividend(32, 2, true);
+ bool Overflow = false;
+ auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_FALSE(Overflow);
+ EXPECT_EQ(-2, quotient.getSExtValue());
+ }
+ // test positive quotient
+ {
+ APInt divisor(32, 3, true);
+ APInt dividend(32, 2, true);
+ bool Overflow = false;
+ auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_FALSE(Overflow);
+ EXPECT_EQ(1, quotient.getSExtValue());
+ }
+ // test overflow
+ {
+ auto check_overflow_one = [](auto arg) {
+ using IntTy = decltype(arg);
+ APInt divisor(8 * sizeof(arg), std::numeric_limits<IntTy>::lowest(),
+ true);
+ APInt dividend(8 * sizeof(arg), IntTy(-1), true);
+ bool Overflow = false;
+ [[maybe_unused]] auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_TRUE(Overflow);
+ };
+ auto check_overflow_all = [&](auto... args) {
+ (void)std::initializer_list<int>{(check_overflow_one(args), 0)...};
+ };
+ std::apply(check_overflow_all, std::tuple<char, short, int, int64_t>());
+ }
+}
+
TEST(APIntTest, SolveQuadraticEquationWrap) {
// Verify that "Solution" is the first non-negative integer that solves
// Ax^2 + Bx + C = "0 or overflow", i.e. that it is a correct solution
>From d1a2ea9b0434c3f979be17a2649a7f9e52efe7f8 Mon Sep 17 00:00:00 2001
From: lipracer <lipracer at gmail.com>
Date: Mon, 11 Mar 2024 14:29:16 +0800
Subject: [PATCH 2/4] refine
---
llvm/lib/Support/APInt.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 8fad85b2d0bccb..2f86c3932ab155 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -2026,8 +2026,7 @@ APInt APInt::sfloordiv_ov(const APInt &RHS, bool &Overflow) const {
auto quotient = sdiv_ov(RHS, Overflow);
if ((quotient * RHS != *this) && (isNegative() != RHS.isNegative()))
return quotient - 1;
- else
- return quotient;
+ return quotient;
}
APInt APInt::sadd_sat(const APInt &RHS) const {
>From 199bf4232aeadc54c62596c0e5eafb13e7e01918 Mon Sep 17 00:00:00 2001
From: lipracer <lipracer at gmail.com>
Date: Thu, 14 Mar 2024 14:13:56 +0800
Subject: [PATCH 3/4] refine
---
llvm/include/llvm/ADT/APInt.h | 5 +++
llvm/lib/Support/APInt.cpp | 2 +-
llvm/unittests/ADT/APIntTest.cpp | 76 ++++++++++++++++++++++++++------
3 files changed, 68 insertions(+), 15 deletions(-)
diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index b91aaa688013a9..1abea9eb24a3c4 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -996,6 +996,11 @@ class [[nodiscard]] APInt {
APInt sshl_ov(unsigned Amt, bool &Overflow) const;
APInt ushl_ov(const APInt &Amt, bool &Overflow) const;
APInt ushl_ov(unsigned Amt, bool &Overflow) const;
+
+ /// Signed integer floor division operation.
+ ///
+ /// Rounds towards negative infinity, i.e. 5 / -2 = -3. Iff minimum value
+ /// divided by -1 set Overflow to true.
APInt sfloordiv_ov(const APInt &RHS, bool &Overflow) const;
// Operations that saturate
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 2f86c3932ab155..fb7c45cece2970 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -2023,7 +2023,7 @@ APInt APInt::ushl_ov(unsigned ShAmt, bool &Overflow) const {
}
APInt APInt::sfloordiv_ov(const APInt &RHS, bool &Overflow) const {
- auto quotient = sdiv_ov(RHS, Overflow);
+ APInt quotient = sdiv_ov(RHS, Overflow);
if ((quotient * RHS != *this) && (isNegative() != RHS.isNegative()))
return quotient - 1;
return quotient;
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 749dd98efd260c..076a0c6fe24b05 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -3068,21 +3068,69 @@ TEST(APIntTest, sfloordiv_ov) {
EXPECT_FALSE(Overflow);
EXPECT_EQ(1, quotient.getSExtValue());
}
- // test overflow
+ // int8 test overflow
{
- auto check_overflow_one = [](auto arg) {
- using IntTy = decltype(arg);
- APInt divisor(8 * sizeof(arg), std::numeric_limits<IntTy>::lowest(),
- true);
- APInt dividend(8 * sizeof(arg), IntTy(-1), true);
- bool Overflow = false;
- [[maybe_unused]] auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
- EXPECT_TRUE(Overflow);
- };
- auto check_overflow_all = [&](auto... args) {
- (void)std::initializer_list<int>{(check_overflow_one(args), 0)...};
- };
- std::apply(check_overflow_all, std::tuple<char, short, int, int64_t>());
+ using IntTy = int8_t;
+ APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+ true);
+ APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+ bool Overflow = false;
+ (void)divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_TRUE(Overflow);
+ }
+ // int16 test overflow
+ {
+ using IntTy = int16_t;
+ APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+ true);
+ APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+ bool Overflow = false;
+ (void)divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_TRUE(Overflow);
+ }
+ // int32 test overflow
+ {
+ using IntTy = int32_t;
+ APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+ true);
+ APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+ bool Overflow = false;
+ (void)divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_TRUE(Overflow);
+ }
+ // int64 test overflow
+ {
+ using IntTy = int64_t;
+ APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
+ true);
+ APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
+ bool Overflow = false;
+ (void)divisor.sfloordiv_ov(dividend, Overflow);
+ EXPECT_TRUE(Overflow);
+ }
+ // test all of int8
+ {
+ bool Overflow = true;
+ for (int i = -128; i < 128; ++i) {
+ for (int j = -128; j < 128; ++j) {
+ if (j == 0 || (i == -128 && j == -1))
+ continue;
+ int8_t a = static_cast<int8_t>(i);
+ int8_t b = static_cast<int8_t>(j);
+
+ APInt divisor(8, a, true);
+ APInt dividend(8, b, true);
+ if (((i >= 0 && j > 0) || (i <= 0 && j < 0)) ||
+ (i % j == 0)) // if quotient >= 0 and remain == 0 floordiv
+ // equivalent to div
+ EXPECT_EQ(divisor.sfloordiv_ov(dividend, Overflow).getSExtValue(),
+ a / b);
+ else
+ EXPECT_EQ(divisor.sfloordiv_ov(dividend, Overflow).getSExtValue(),
+ a / b - 1);
+ EXPECT_FALSE(Overflow);
+ }
+ }
}
}
>From 91666309f53b9c0955447495bac38da2138cbfe2 Mon Sep 17 00:00:00 2001
From: lipracer <lipracer at gmail.com>
Date: Thu, 14 Mar 2024 21:49:26 +0800
Subject: [PATCH 4/4] remove redundant test case
---
llvm/unittests/ADT/APIntTest.cpp | 46 +++++++++-----------------------
1 file changed, 12 insertions(+), 34 deletions(-)
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 076a0c6fe24b05..6aec1049584bbe 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -3050,34 +3050,6 @@ TEST(APIntTest, smul_ov) {
}
TEST(APIntTest, sfloordiv_ov) {
- // test negative quotient
- {
- APInt divisor(32, -3, true);
- APInt dividend(32, 2, true);
- bool Overflow = false;
- auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
- EXPECT_FALSE(Overflow);
- EXPECT_EQ(-2, quotient.getSExtValue());
- }
- // test positive quotient
- {
- APInt divisor(32, 3, true);
- APInt dividend(32, 2, true);
- bool Overflow = false;
- auto quotient = divisor.sfloordiv_ov(dividend, Overflow);
- EXPECT_FALSE(Overflow);
- EXPECT_EQ(1, quotient.getSExtValue());
- }
- // int8 test overflow
- {
- using IntTy = int8_t;
- APInt divisor(8 * sizeof(IntTy), std::numeric_limits<IntTy>::lowest(),
- true);
- APInt dividend(8 * sizeof(IntTy), IntTy(-1), true);
- bool Overflow = false;
- (void)divisor.sfloordiv_ov(dividend, Overflow);
- EXPECT_TRUE(Overflow);
- }
// int16 test overflow
{
using IntTy = int16_t;
@@ -3110,24 +3082,30 @@ TEST(APIntTest, sfloordiv_ov) {
}
// test all of int8
{
- bool Overflow = true;
+ bool Overflow = false;
for (int i = -128; i < 128; ++i) {
for (int j = -128; j < 128; ++j) {
- if (j == 0 || (i == -128 && j == -1))
+ if (j == 0)
continue;
+
int8_t a = static_cast<int8_t>(i);
int8_t b = static_cast<int8_t>(j);
APInt divisor(8, a, true);
APInt dividend(8, b, true);
+ APInt quotient = divisor.sfloordiv_ov(dividend, Overflow);
+
+ if (i == -128 && j == -1) {
+ EXPECT_TRUE(Overflow);
+ continue;
+ }
+
if (((i >= 0 && j > 0) || (i <= 0 && j < 0)) ||
(i % j == 0)) // if quotient >= 0 and remain == 0 floordiv
// equivalent to div
- EXPECT_EQ(divisor.sfloordiv_ov(dividend, Overflow).getSExtValue(),
- a / b);
+ EXPECT_EQ(quotient.getSExtValue(), a / b);
else
- EXPECT_EQ(divisor.sfloordiv_ov(dividend, Overflow).getSExtValue(),
- a / b - 1);
+ EXPECT_EQ(quotient.getSExtValue(), a / b - 1);
EXPECT_FALSE(Overflow);
}
}
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