[libc-commits] [libc] [libc] Add compound assignment operator overloads for BFloat16 (PR #201301)
via libc-commits
libc-commits at lists.llvm.org
Wed Jun 3 04:52:46 PDT 2026
https://github.com/Sukumarsawant updated https://github.com/llvm/llvm-project/pull/201301
>From 56ee4e624bb0075b31ae133131d5688fa5f332f4 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 15:03:17 +0530
Subject: [PATCH 1/4] feat:const Bfloat16 & + additional operator + smoke
---
libc/src/__support/FPUtil/bfloat16.h | 32 ++++++++++-----
.../src/__support/FPUtil/bfloat16_test.cpp | 39 ++++++++++++++++++-
2 files changed, 60 insertions(+), 11 deletions(-)
diff --git a/libc/src/__support/FPUtil/bfloat16.h b/libc/src/__support/FPUtil/bfloat16.h
index 638500d94cef2..0816d3442b8fc 100644
--- a/libc/src/__support/FPUtil/bfloat16.h
+++ b/libc/src/__support/FPUtil/bfloat16.h
@@ -68,27 +68,27 @@ struct BFloat16 {
return static_cast<T>(static_cast<float>(*this));
}
- LIBC_INLINE constexpr bool operator==(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator==(const BFloat16 &other) const {
return fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator!=(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator!=(const BFloat16 &other) const {
return !fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator<(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator<(const BFloat16 &other) const {
return fputil::less_than(*this, other);
}
- LIBC_INLINE constexpr bool operator<=(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator<=(const BFloat16 &other) const {
return fputil::less_than_or_equals(*this, other);
}
- LIBC_INLINE constexpr bool operator>(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator>(const BFloat16 &other) const {
return fputil::greater_than(*this, other);
}
- LIBC_INLINE constexpr bool operator>=(BFloat16 other) const {
+ LIBC_INLINE constexpr bool operator>=(const BFloat16 &other) const {
return fputil::greater_than_or_equals(*this, other);
}
@@ -98,19 +98,19 @@ struct BFloat16 {
return result.get_val();
}
- LIBC_INLINE constexpr BFloat16 operator+(BFloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator+(const BFloat16 &other) const {
return fputil::generic::add<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator-(BFloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator-(const BFloat16 &other) const {
return fputil::generic::sub<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator*(BFloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator*(const BFloat16 &other) const {
return fputil::generic::mul<bfloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator/(BFloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator/(const BFloat16 &other) const {
return fputil::generic::div<bfloat16>(*this, other);
}
@@ -118,6 +118,18 @@ struct BFloat16 {
*this = *this * other;
return *this;
}
+ LIBC_INLINE constexpr BFloat16 &operator+=(const BFloat16 &other) {
+ *this = *this + other;
+ return *this;
+ }
+ LIBC_INLINE constexpr BFloat16 &operator-=(const BFloat16 &other) {
+ *this = *this - other;
+ return *this;
+ }
+ LIBC_INLINE constexpr BFloat16 &operator/=(const BFloat16 &other) {
+ *this = *this / other;
+ return *this;
+ }
}; // struct BFloat16
} // namespace fputil
diff --git a/libc/test/src/__support/FPUtil/bfloat16_test.cpp b/libc/test/src/__support/FPUtil/bfloat16_test.cpp
index 8760b2abe3ce3..9ea97ad842d5f 100644
--- a/libc/test/src/__support/FPUtil/bfloat16_test.cpp
+++ b/libc/test/src/__support/FPUtil/bfloat16_test.cpp
@@ -68,12 +68,13 @@ TEST_F(LlvmLibcBfloat16ConversionTest, FromInteger) {
}
}
-TEST_F(LlvmLibcBfloat16ConversionTest, MultiplyAssign) {
+TEST_F(LlvmLibcBfloat16ConversionTest, shortHandOperators) {
constexpr BFloat16 VAL[] = {zero, neg_zero, inf,
neg_inf, min_normal, max_normal,
bfloat16(1.0f), bfloat16(-1.0f), bfloat16(2.0f),
bfloat16(3.0f)};
+ // *=
for (const bfloat16 &x : VAL) {
for (const bfloat16 &y : VAL) {
BFloat16 a = x, b = y;
@@ -85,4 +86,40 @@ TEST_F(LlvmLibcBfloat16ConversionTest, MultiplyAssign) {
EXPECT_FP_EQ_ALL_ROUNDING(mpfr_bfloat, libc_bfloat);
}
}
+ // /=
+ for (const bfloat16 &x : VAL) {
+ for (const bfloat16 &y : VAL) {
+ BFloat16 a = x, b = y;
+ MPFRNumber mpfr_a{a}, mpfr_b{b};
+ MPFRNumber mpfr_c = mpfr_a.div(mpfr_b);
+ BFloat16 mpfr_bfloat = mpfr_c.as<BFloat16>();
+ a /= b;
+ BFloat16 libc_bfloat = a;
+ EXPECT_FP_EQ_ALL_ROUNDING(mpfr_bfloat, libc_bfloat);
+ }
+ }
+ // +=
+ for (const bfloat16 &x : VAL) {
+ for (const bfloat16 &y : VAL) {
+ BFloat16 a = x, b = y;
+ MPFRNumber mpfr_a{a}, mpfr_b{b};
+ MPFRNumber mpfr_c = mpfr_a.add(mpfr_b);
+ BFloat16 mpfr_bfloat = mpfr_c.as<BFloat16>();
+ a += b;
+ BFloat16 libc_bfloat = a;
+ EXPECT_FP_EQ_ALL_ROUNDING(mpfr_bfloat, libc_bfloat);
+ }
+ }
+ // -=
+ for (const bfloat16 &x : VAL) {
+ for (const bfloat16 &y : VAL) {
+ BFloat16 a = x, b = y;
+ MPFRNumber mpfr_a{a}, mpfr_b{b};
+ MPFRNumber mpfr_c = mpfr_a.sub(mpfr_b);
+ BFloat16 mpfr_bfloat = mpfr_c.as<BFloat16>();
+ a -= b;
+ BFloat16 libc_bfloat = a;
+ EXPECT_FP_EQ_ALL_ROUNDING(mpfr_bfloat, libc_bfloat);
+ }
+ }
}
>From 2ccfcd81ae16e441d6f2af46ab42b1e6f74c5650 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 17:13:46 +0530
Subject: [PATCH 2/4] switch to pass-by-val
---
libc/src/__support/FPUtil/bfloat16.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/libc/src/__support/FPUtil/bfloat16.h b/libc/src/__support/FPUtil/bfloat16.h
index 0816d3442b8fc..eae6b6e27a6d2 100644
--- a/libc/src/__support/FPUtil/bfloat16.h
+++ b/libc/src/__support/FPUtil/bfloat16.h
@@ -68,27 +68,27 @@ struct BFloat16 {
return static_cast<T>(static_cast<float>(*this));
}
- LIBC_INLINE constexpr bool operator==(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator==(Bfloat16 other) const {
return fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator!=(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator!=(Bfloat16 other) const {
return !fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator<(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator<(Bfloat16 other) const {
return fputil::less_than(*this, other);
}
- LIBC_INLINE constexpr bool operator<=(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator<=(Bfloat16 other) const {
return fputil::less_than_or_equals(*this, other);
}
- LIBC_INLINE constexpr bool operator>(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator>(Bfloat16 other) const {
return fputil::greater_than(*this, other);
}
- LIBC_INLINE constexpr bool operator>=(const BFloat16 &other) const {
+ LIBC_INLINE constexpr bool operator>=(Bfloat16 other) const {
return fputil::greater_than_or_equals(*this, other);
}
@@ -98,35 +98,35 @@ struct BFloat16 {
return result.get_val();
}
- LIBC_INLINE constexpr BFloat16 operator+(const BFloat16 &other) const {
+ LIBC_INLINE constexpr BFloat16 operator+(Bfloat16 other) const {
return fputil::generic::add<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator-(const BFloat16 &other) const {
+ LIBC_INLINE constexpr BFloat16 operator-(Bfloat16 other) const {
return fputil::generic::sub<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator*(const BFloat16 &other) const {
+ LIBC_INLINE constexpr BFloat16 operator*(Bfloat16 other) const {
return fputil::generic::mul<bfloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator/(const BFloat16 &other) const {
+ LIBC_INLINE constexpr BFloat16 operator/(Bfloat16 other) const {
return fputil::generic::div<bfloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 &operator*=(const BFloat16 &other) {
+ LIBC_INLINE constexpr BFloat16 &operator*=(Bfloat16 other) {
*this = *this * other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator+=(const BFloat16 &other) {
+ LIBC_INLINE constexpr BFloat16 &operator+=(Bfloat16 other) {
*this = *this + other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator-=(const BFloat16 &other) {
+ LIBC_INLINE constexpr BFloat16 &operator-=(Bfloat16 other) {
*this = *this - other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator/=(const BFloat16 &other) {
+ LIBC_INLINE constexpr BFloat16 &operator/=(Bfloat16 other) {
*this = *this / other;
return *this;
}
>From 78930eeeaa7803c6dd567879dfaae1052124d589 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 17:15:19 +0530
Subject: [PATCH 3/4] chore: rename
---
libc/test/src/__support/FPUtil/bfloat16_test.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libc/test/src/__support/FPUtil/bfloat16_test.cpp b/libc/test/src/__support/FPUtil/bfloat16_test.cpp
index 9ea97ad842d5f..28333cfc18441 100644
--- a/libc/test/src/__support/FPUtil/bfloat16_test.cpp
+++ b/libc/test/src/__support/FPUtil/bfloat16_test.cpp
@@ -68,7 +68,7 @@ TEST_F(LlvmLibcBfloat16ConversionTest, FromInteger) {
}
}
-TEST_F(LlvmLibcBfloat16ConversionTest, shortHandOperators) {
+TEST_F(LlvmLibcBfloat16ConversionTest, compoundAssignmentOperators) {
constexpr BFloat16 VAL[] = {zero, neg_zero, inf,
neg_inf, min_normal, max_normal,
>From 6ce243b008771897c038622739cb6811577fb383 Mon Sep 17 00:00:00 2001
From: Sukumarsawant <sawantsukumar at gmail.com>
Date: Wed, 3 Jun 2026 17:22:24 +0530
Subject: [PATCH 4/4] nit
---
libc/src/__support/FPUtil/bfloat16.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/libc/src/__support/FPUtil/bfloat16.h b/libc/src/__support/FPUtil/bfloat16.h
index eae6b6e27a6d2..ce4e3160a0963 100644
--- a/libc/src/__support/FPUtil/bfloat16.h
+++ b/libc/src/__support/FPUtil/bfloat16.h
@@ -68,27 +68,27 @@ struct BFloat16 {
return static_cast<T>(static_cast<float>(*this));
}
- LIBC_INLINE constexpr bool operator==(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator==(BFloat16 other) const {
return fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator!=(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator!=(BFloat16 other) const {
return !fputil::equals(*this, other);
}
- LIBC_INLINE constexpr bool operator<(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator<(BFloat16 other) const {
return fputil::less_than(*this, other);
}
- LIBC_INLINE constexpr bool operator<=(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator<=(BFloat16 other) const {
return fputil::less_than_or_equals(*this, other);
}
- LIBC_INLINE constexpr bool operator>(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator>(BFloat16 other) const {
return fputil::greater_than(*this, other);
}
- LIBC_INLINE constexpr bool operator>=(Bfloat16 other) const {
+ LIBC_INLINE constexpr bool operator>=(BFloat16 other) const {
return fputil::greater_than_or_equals(*this, other);
}
@@ -98,35 +98,35 @@ struct BFloat16 {
return result.get_val();
}
- LIBC_INLINE constexpr BFloat16 operator+(Bfloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator+(BFloat16 other) const {
return fputil::generic::add<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator-(Bfloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator-(BFloat16 other) const {
return fputil::generic::sub<BFloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator*(Bfloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator*(BFloat16 other) const {
return fputil::generic::mul<bfloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 operator/(Bfloat16 other) const {
+ LIBC_INLINE constexpr BFloat16 operator/(BFloat16 other) const {
return fputil::generic::div<bfloat16>(*this, other);
}
- LIBC_INLINE constexpr BFloat16 &operator*=(Bfloat16 other) {
+ LIBC_INLINE constexpr BFloat16 &operator*=(BFloat16 other) {
*this = *this * other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator+=(Bfloat16 other) {
+ LIBC_INLINE constexpr BFloat16 &operator+=(BFloat16 other) {
*this = *this + other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator-=(Bfloat16 other) {
+ LIBC_INLINE constexpr BFloat16 &operator-=(BFloat16 other) {
*this = *this - other;
return *this;
}
- LIBC_INLINE constexpr BFloat16 &operator/=(Bfloat16 other) {
+ LIBC_INLINE constexpr BFloat16 &operator/=(BFloat16 other) {
*this = *this / other;
return *this;
}
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