[llvm] 0d53366 - APFloat: Add minimumnum and maximumnum (#96304)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Jun 25 16:10:46 PDT 2024
Author: YunQiang Su
Date: 2024-06-26T07:10:43+08:00
New Revision: 0d533665054c3a04681c46f3ed88960f28777be1
URL: https://github.com/llvm/llvm-project/commit/0d533665054c3a04681c46f3ed88960f28777be1
DIFF: https://github.com/llvm/llvm-project/commit/0d533665054c3a04681c46f3ed88960f28777be1.diff
LOG: APFloat: Add minimumnum and maximumnum (#96304)
They implements IEEE754-2019 minimumNumber and maximumNumber semantics.
Newer libc also has these 2 functions with names
fminimum_num
fmaximum_num
We are planning add minimumnum and maximumnum intrinsic. This is a step
to the goal.
Added:
Modified:
llvm/include/llvm/ADT/APFloat.h
llvm/unittests/ADT/APFloatTest.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/ADT/APFloat.h b/llvm/include/llvm/ADT/APFloat.h
index c24eae8da3797..db2fa480655c6 100644
--- a/llvm/include/llvm/ADT/APFloat.h
+++ b/llvm/include/llvm/ADT/APFloat.h
@@ -1483,6 +1483,19 @@ inline APFloat minimum(const APFloat &A, const APFloat &B) {
return B < A ? B : A;
}
+/// Implements IEEE 754-2019 minimumNumber semantics. Returns the smaller
+/// of 2 arguments, not propagating NaNs and treating -0 as less than +0.
+LLVM_READONLY
+inline APFloat minimumnum(const APFloat &A, const APFloat &B) {
+ if (A.isNaN())
+ return B.isNaN() ? B.makeQuiet() : B;
+ if (B.isNaN())
+ return A;
+ if (A.isZero() && B.isZero() && (A.isNegative() != B.isNegative()))
+ return A.isNegative() ? A : B;
+ return B < A ? B : A;
+}
+
/// Implements IEEE 754-2019 maximum semantics. Returns the larger of 2
/// arguments, propagating NaNs and treating -0 as less than +0.
LLVM_READONLY
@@ -1496,6 +1509,19 @@ inline APFloat maximum(const APFloat &A, const APFloat &B) {
return A < B ? B : A;
}
+/// Implements IEEE 754-2019 maximumNumber semantics. Returns the larger
+/// of 2 arguments, not propagating NaNs and treating -0 as less than +0.
+LLVM_READONLY
+inline APFloat maximumnum(const APFloat &A, const APFloat &B) {
+ if (A.isNaN())
+ return B.isNaN() ? B.makeQuiet() : B;
+ if (B.isNaN())
+ return A;
+ if (A.isZero() && B.isZero() && (A.isNegative() != B.isNegative()))
+ return A.isNegative() ? B : A;
+ return A < B ? B : A;
+}
+
// We want the following functions to be available in the header for inlining.
// We cannot define them inline in the class definition of `DoubleAPFloat`
// because doing so would instantiate `std::unique_ptr<APFloat[]>` before
diff --git a/llvm/unittests/ADT/APFloatTest.cpp b/llvm/unittests/ADT/APFloatTest.cpp
index f6af4b0e5f651..cf6bbd313c6c6 100644
--- a/llvm/unittests/ADT/APFloatTest.cpp
+++ b/llvm/unittests/ADT/APFloatTest.cpp
@@ -631,6 +631,100 @@ TEST(APFloatTest, Maximum) {
EXPECT_TRUE(std::isnan(maximum(nan, f1).convertToDouble()));
}
+TEST(APFloatTest, MinimumNumber) {
+ APFloat f1(1.0);
+ APFloat f2(2.0);
+ APFloat zp(0.0);
+ APFloat zn(-0.0);
+ APInt intPayload_89ab(64, 0x89ab);
+ APInt intPayload_cdef(64, 0xcdef);
+ APFloat nan_0123[2] = {APFloat::getNaN(APFloat::IEEEdouble(), false, 0x0123),
+ APFloat::getNaN(APFloat::IEEEdouble(), false, 0x0123)};
+ APFloat mnan_4567[2] = {APFloat::getNaN(APFloat::IEEEdouble(), true, 0x4567),
+ APFloat::getNaN(APFloat::IEEEdouble(), true, 0x4567)};
+ APFloat nan_89ab[2] = {
+ APFloat::getSNaN(APFloat::IEEEdouble(), false, &intPayload_89ab),
+ APFloat::getNaN(APFloat::IEEEdouble(), false, 0x89ab)};
+ APFloat mnan_cdef[2] = {
+ APFloat::getSNaN(APFloat::IEEEdouble(), true, &intPayload_cdef),
+ APFloat::getNaN(APFloat::IEEEdouble(), true, 0xcdef)};
+
+ EXPECT_TRUE(f1.bitwiseIsEqual(minimumnum(f1, f2)));
+ EXPECT_TRUE(f1.bitwiseIsEqual(minimumnum(f2, f1)));
+ EXPECT_TRUE(zn.bitwiseIsEqual(minimumnum(zp, zn)));
+ EXPECT_TRUE(zn.bitwiseIsEqual(minimumnum(zn, zp)));
+
+ EXPECT_TRUE(minimumnum(zn, zp).isNegative());
+ EXPECT_TRUE(minimumnum(zp, zn).isNegative());
+ EXPECT_TRUE(minimumnum(zn, zn).isNegative());
+ EXPECT_FALSE(minimumnum(zp, zp).isNegative());
+
+ for (APFloat n : {nan_0123[0], mnan_4567[0], nan_89ab[0], mnan_cdef[0]})
+ for (APFloat f : {f1, f2, zn, zp}) {
+ APFloat res = minimumnum(f, n);
+ EXPECT_FALSE(res.isNaN());
+ EXPECT_TRUE(res.bitwiseIsEqual(f));
+ res = minimumnum(n, f);
+ EXPECT_FALSE(res.isNaN());
+ EXPECT_TRUE(res.bitwiseIsEqual(f));
+ }
+
+ // When NaN vs NaN, we should keep payload/sign of either one.
+ for (auto n1 : {nan_0123, mnan_4567, nan_89ab, mnan_cdef})
+ for (auto n2 : {nan_0123, mnan_4567, nan_89ab, mnan_cdef}) {
+ APFloat res = minimumnum(n1[0], n2[0]);
+ EXPECT_TRUE(res.bitwiseIsEqual(n1[1]) || res.bitwiseIsEqual(n2[1]));
+ EXPECT_FALSE(res.isSignaling());
+ }
+}
+
+TEST(APFloatTest, MaximumNumber) {
+ APFloat f1(1.0);
+ APFloat f2(2.0);
+ APFloat zp(0.0);
+ APFloat zn(-0.0);
+ APInt intPayload_89ab(64, 0x89ab);
+ APInt intPayload_cdef(64, 0xcdef);
+ APFloat nan_0123[2] = {APFloat::getNaN(APFloat::IEEEdouble(), false, 0x0123),
+ APFloat::getNaN(APFloat::IEEEdouble(), false, 0x0123)};
+ APFloat mnan_4567[2] = {APFloat::getNaN(APFloat::IEEEdouble(), true, 0x4567),
+ APFloat::getNaN(APFloat::IEEEdouble(), true, 0x4567)};
+ APFloat nan_89ab[2] = {
+ APFloat::getSNaN(APFloat::IEEEdouble(), false, &intPayload_89ab),
+ APFloat::getNaN(APFloat::IEEEdouble(), false, 0x89ab)};
+ APFloat mnan_cdef[2] = {
+ APFloat::getSNaN(APFloat::IEEEdouble(), true, &intPayload_cdef),
+ APFloat::getNaN(APFloat::IEEEdouble(), true, 0xcdef)};
+
+ EXPECT_TRUE(f2.bitwiseIsEqual(maximumnum(f1, f2)));
+ EXPECT_TRUE(f2.bitwiseIsEqual(maximumnum(f2, f1)));
+ EXPECT_TRUE(zp.bitwiseIsEqual(maximumnum(zp, zn)));
+ EXPECT_TRUE(zp.bitwiseIsEqual(maximumnum(zn, zp)));
+
+ EXPECT_FALSE(maximumnum(zn, zp).isNegative());
+ EXPECT_FALSE(maximumnum(zp, zn).isNegative());
+ EXPECT_TRUE(maximumnum(zn, zn).isNegative());
+ EXPECT_FALSE(maximumnum(zp, zp).isNegative());
+
+ for (APFloat n : {nan_0123[0], mnan_4567[0], nan_89ab[0], mnan_cdef[0]})
+ for (APFloat f : {f1, f2, zn, zp}) {
+ APFloat res = maximumnum(f, n);
+ EXPECT_FALSE(res.isNaN());
+ EXPECT_TRUE(res.bitwiseIsEqual(f));
+ res = maximumnum(n, f);
+ EXPECT_FALSE(res.isNaN());
+ EXPECT_TRUE(res.bitwiseIsEqual(f));
+ }
+
+ // When NaN vs NaN, we should keep payload/sign of either one.
+ for (auto n1 : {nan_0123, mnan_4567, nan_89ab, mnan_cdef})
+ for (auto n2 : {nan_0123, mnan_4567, nan_89ab, mnan_cdef}) {
+ APFloat res = maximumnum(n1[0], n2[0]);
+ EXPECT_TRUE(res.bitwiseIsEqual(n1[1]) || res.bitwiseIsEqual(n2[1]));
+ EXPECT_FALSE(res.isSignaling());
+ }
+}
+
TEST(APFloatTest, Denormal) {
APFloat::roundingMode rdmd = APFloat::rmNearestTiesToEven;
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