pgvector.git / summary / log / commit / refs

commit    3eba34e5e37bf6fe651e7c98b232ef8ffdc75fdd
Author:   Andrew Kane <andrew@ankane.org>
Date:     Mon Apr 08 21:40:12 2024 +0000

    Improved code for feature detection


 src/halfutils.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/halfutils.c b/src/halfutils.c
index c53da83d..7485e9d8 100644
--- a/src/halfutils.c
+++ b/src/halfutils.c
@@ -118,8 +118,11 @@ HalfvecInnerProductF16cFma(int dim, half * ax, half * bx)
 #endif
 
 #ifdef HALFVEC_DISPATCH
+#define FEATURE_FMA  (1 << 12)
+#define FEATURE_F16C (1 << 29)
+
 static bool
-F16cFmaAvailable()
+SupportsFeature(unsigned int feature)
 {
 	unsigned int exx[4] = {0, 0, 0, 0};
 
@@ -129,8 +132,7 @@ F16cFmaAvailable()
 	__cpuid(exx, 1);
 #endif
 
-	/* FMA = 12, F16C = 29 */
-	return (exx[2] & (1 << 12)) != 0 && (exx[2] & (1 << 29)) != 0;
+	return (exx[2] & feature) == feature;
 }
 #endif
 
@@ -145,7 +147,7 @@ HalfvecInit(void)
 	HalfvecInnerProduct = HalfvecInnerProductDefault;
 
 #ifdef HALFVEC_DISPATCH
-	if (F16cFmaAvailable())
+	if (SupportsFeature(FEATURE_FMA | FEATURE_F16C))
 	{
 		HalfvecL2DistanceSquared = HalfvecL2DistanceSquaredF16cFma;
 		HalfvecInnerProduct = HalfvecInnerProductF16cFma;


[parent: 862f17c1de9f]