ssemath: Fix RotateRight behavior as expected (a b c d -> d a b c)

dimhotepus · mastercoms · commit 42dbaae16f9c · 2025-02-22T20:10:33.000-05:00
Closes ValveSoftware#747
diff --git a/src/public/mathlib/ssemath.h b/src/public/mathlib/ssemath.h
@@ -1982,7 +1982,7 @@ FORCEINLINE fltx4 RotateLeft2( const fltx4 & a )
 // a b c d -> d a b c
 FORCEINLINE fltx4 RotateRight( const fltx4 & a )
 {
-	return _mm_shuffle_ps( a, a, _MM_SHUFFLE( 0, 3, 2, 1) );
+	return _mm_shuffle_ps( a, a, MM_SHUFFLE_REV( 3, 0, 1, 2 ) );
 }
 
 // a b c d -> c d a b

Original file line number	Diff line number	Diff line change
`@@ -1982,7 +1982,7 @@ FORCEINLINE fltx4 RotateLeft2( const fltx4 & a )`
`1982`	`1982`	`// a b c d -> d a b c`
`1983`	`1983`	`FORCEINLINE fltx4 RotateRight( const fltx4 & a )`
`1984`	`1984`	`{`
`1985`		`- return _mm_shuffle_ps( a, a, _MM_SHUFFLE( 0, 3, 2, 1) );`
	`1985`	`+ return _mm_shuffle_ps( a, a, MM_SHUFFLE_REV( 3, 0, 1, 2 ) );`
`1986`	`1986`	`}`
`1987`	`1987`
`1988`	`1988`	`// a b c d -> c d a b`