From: ratchov <ratchov@openbsd.org>
Date: Tue, 25 May 2021 08:06:12 +0000 (+0000)
Subject: Drop assembly for 24-bit fixed-point operations
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ac5d4608a4bc3b7e29c6e7c48595a61443b00931;p=openbsd

Drop assembly for 24-bit fixed-point operations

Now i386 compiler is smart enough to generate a single imul
instruction per fixed-point multiplication. This change also allows
24-bit precision to be used on all archs (if -DADATA_BITS=24 is used).

Tested on arm64 by Doug Moss <dougmoss710 at yahoo.com>, thanks

Suggested and ok naddy@
---

diff --git a/usr.bin/aucat/dsp.h b/usr.bin/aucat/dsp.h
index 2758147ce69..925ccf23abb 100644
--- a/usr.bin/aucat/dsp.h
+++ b/usr.bin/aucat/dsp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dsp.h,v 1.7 2021/01/12 15:46:53 naddy Exp $	*/
+/*	$OpenBSD: dsp.h,v 1.8 2021/05/25 08:06:12 ratchov Exp $	*/
 /*
  * Copyright (c) 2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -34,56 +34,13 @@
 #if ADATA_BITS == 16
 
 #define ADATA_MUL(x,y)		(((int)(x) * (int)(y)) >> (ADATA_BITS - 1))
-#define ADATA_MULDIV(x,y,z)	((int)(x) * (int)(y) / (int)(z))
 
 typedef short adata_t;
 
 #elif ADATA_BITS == 24
 
-#if defined(__i386__) && defined(__GNUC__)
-
-static inline int
-fp24_mul(int x, int a)
-{
-	int res;
-
-	asm volatile (
-		"imull	%2\n\t"
-		"shrdl $23, %%edx, %%eax\n\t"
-		: "=a" (res)
-		: "a" (x), "r" (a)
-		: "%edx"
-		);
-	return res;
-}
-
-static inline int
-fp24_muldiv(int x, int a, int b)
-{
-	int res;
-
-	asm volatile (
-		"imull %2\n\t"
-		"idivl %3\n\t"
-		: "=a" (res)
-		: "a" (x), "d" (a), "r" (b)
-		);
-	return res;
-}
-
-#define ADATA_MUL(x,y)		fp24_mul(x, y)
-#define ADATA_MULDIV(x,y,z)	fp24_muldiv(x, y, z);
-
-#elif defined(__amd64__) || defined(__sparc64__)
-
 #define ADATA_MUL(x,y)		\
 	((int)(((long long)(x) * (long long)(y)) >> (ADATA_BITS - 1)))
-#define ADATA_MULDIV(x,y,z)	\
-	((int)((long long)(x) * (long long)(y) / (long long)(z)))
-
-#else
-#error "no 24-bit code for this architecture"
-#endif
 
 typedef int adata_t;
 
diff --git a/usr.bin/sndiod/dsp.h b/usr.bin/sndiod/dsp.h
index 71cae26d9fe..539889c7f2e 100644
--- a/usr.bin/sndiod/dsp.h
+++ b/usr.bin/sndiod/dsp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dsp.h,v 1.9 2021/01/12 15:46:53 naddy Exp $	*/
+/*	$OpenBSD: dsp.h,v 1.10 2021/05/25 08:06:12 ratchov Exp $	*/
 /*
  * Copyright (c) 2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -34,56 +34,13 @@
 #if ADATA_BITS == 16
 
 #define ADATA_MUL(x,y)		(((int)(x) * (int)(y)) >> (ADATA_BITS - 1))
-#define ADATA_MULDIV(x,y,z)	((int)(x) * (int)(y) / (int)(z))
 
 typedef short adata_t;
 
 #elif ADATA_BITS == 24
 
-#if defined(__i386__) && defined(__GNUC__)
-
-static inline int
-fp24_mul(int x, int a)
-{
-	int res;
-
-	asm volatile (
-		"imull	%2\n\t"
-		"shrdl $23, %%edx, %%eax\n\t"
-		: "=a" (res)
-		: "a" (x), "r" (a)
-		: "%edx"
-		);
-	return res;
-}
-
-static inline int
-fp24_muldiv(int x, int a, int b)
-{
-	int res;
-
-	asm volatile (
-		"imull %2\n\t"
-		"idivl %3\n\t"
-		: "=a" (res)
-		: "a" (x), "d" (a), "r" (b)
-		);
-	return res;
-}
-
-#define ADATA_MUL(x,y)		fp24_mul(x, y)
-#define ADATA_MULDIV(x,y,z)	fp24_muldiv(x, y, z);
-
-#elif defined(__amd64__) || defined(__sparc64__)
-
 #define ADATA_MUL(x,y)		\
 	((int)(((long long)(x) * (long long)(y)) >> (ADATA_BITS - 1)))
-#define ADATA_MULDIV(x,y,z)	\
-	((int)((long long)(x) * (long long)(y) / (long long)(z)))
-
-#else
-#error "no 24-bit code for this architecture"
-#endif
 
 typedef int adata_t;