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 2758147..925ccf2 100644 (file)
--- 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 71cae26..539889c 100644 (file)
--- 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;