From c4f237a98175438e76da64c51cc6fe613f8d767e Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Tue, 3 Jan 2012 16:31:57 +0100
Subject: [PATCH] Revert commit 599b4c6efddaed33b1667c386b34b07729ba732b
Author: Mans Rullgard <mans@mansr.com>
Date: Sun Dec 11 21:41:59 2011 +0000
x86: cabac: replace explicit memory references with "m" operands
This replaces the explicit offset(reg) memory references with
"m" operands for the same locations. As a result, one fewer
register operand is needed for these inline asm statements.
This change appears to have broken compilation on darwin, and subsequent
fixes by martin (which did not fix compilation) removed the register
advantage, thus this change seems not a good idea to keep.
See: http://fate.ffmpeg.org/log.cgi?time=20120103122446&log=compile&slot=i386-darwin-llvm-gcc-4.2.1
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/x86/cabac.h | 49 ++++++++++++++++++++++----------------
libavcodec/x86/h264_i386.h | 27 +++++++++++----------
2 files changed, 43 insertions(+), 33 deletions(-)
diff --git a/libavcodec/x86/cabac.h b/libavcodec/x86/cabac.h
index 3c3652d5f0a..33304ab0f4b 100644
--- a/libavcodec/x86/cabac.h
+++ b/libavcodec/x86/cabac.h
@@ -27,7 +27,7 @@
#include "config.h"
#if HAVE_FAST_CMOV
-#define BRANCHLESS_GET_CABAC_UPDATE(ret, statep, low, lowword, range, tmp)\
+#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp)\
"mov "tmp" , %%ecx \n\t"\
"shl $17 , "tmp" \n\t"\
"cmp "low" , "tmp" \n\t"\
@@ -37,7 +37,7 @@
"xor %%ecx , "ret" \n\t"\
"sub "tmp" , "low" \n\t"
#else /* HAVE_FAST_CMOV */
-#define BRANCHLESS_GET_CABAC_UPDATE(ret, statep, low, lowword, range, tmp)\
+#define BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, range, tmp)\
"mov "tmp" , %%ecx \n\t"\
"shl $17 , "tmp" \n\t"\
"sub "low" , "tmp" \n\t"\
@@ -51,13 +51,14 @@
"xor "tmp" , "ret" \n\t"
#endif /* HAVE_FAST_CMOV */
-#define BRANCHLESS_GET_CABAC(ret, statep, low, lowword, range, tmp, tmpbyte, byte) \
+#define BRANCHLESS_GET_CABAC(ret, cabac, statep, low, lowword, range, tmp, tmpbyte, byte) \
"movzbl "statep" , "ret" \n\t"\
"mov "range" , "tmp" \n\t"\
"and $0xC0 , "range" \n\t"\
"movzbl "MANGLE(ff_h264_lps_range)"("ret", "range", 2), "range" \n\t"\
"sub "range" , "tmp" \n\t"\
- BRANCHLESS_GET_CABAC_UPDATE(ret, statep, low, lowword, range, tmp) \
+ BRANCHLESS_GET_CABAC_UPDATE(ret, cabac, statep, low, lowword, \
+ range, tmp) \
"movzbl " MANGLE(ff_h264_norm_shift) "("range"), %%ecx \n\t"\
"shl %%cl , "range" \n\t"\
"movzbl "MANGLE(ff_h264_mlps_state)"+128("ret"), "tmp" \n\t"\
@@ -65,8 +66,8 @@
"mov "tmpbyte" , "statep" \n\t"\
"test "lowword" , "lowword" \n\t"\
" jnz 1f \n\t"\
- "mov "byte" , %%"REG_c" \n\t"\
- "add"OPSIZE" $2 , "byte" \n\t"\
+ "mov "byte"("cabac"), %%"REG_c" \n\t"\
+ "add"OPSIZE" $2 , "byte "("cabac") \n\t"\
"movzwl (%%"REG_c") , "tmp" \n\t"\
"lea -1("low") , %%ecx \n\t"\
"xor "low" , %%ecx \n\t"\
@@ -86,14 +87,20 @@
static av_always_inline int get_cabac_inline_x86(CABACContext *c,
uint8_t *const state)
{
- int bit, tmp;
+ int bit, low, range, tmp;
__asm__ volatile(
- BRANCHLESS_GET_CABAC("%0", "(%5)", "%1", "%w1", "%2",
- "%3", "%b3", "%4")
- :"=&r"(bit), "+&r"(c->low), "+&r"(c->range), "=&q"(tmp),
- "+m"(c->bytestream)
- :"r"(state)
+ "movl %a6(%5), %2 \n\t"
+ "movl %a7(%5), %1 \n\t"
+ BRANCHLESS_GET_CABAC("%0", "%5", "(%4)", "%1", "%w1", "%2",
+ "%3", "%b3", "%a8")
+ "movl %2, %a6(%5) \n\t"
+ "movl %1, %a7(%5) \n\t"
+
+ :"=&r"(bit), "=&r"(low), "=&r"(range), "=&q"(tmp)
+ :"r"(state), "r"(c),
+ "i"(offsetof(CABACContext, range)), "i"(offsetof(CABACContext, low)),
+ "i"(offsetof(CABACContext, bytestream))
: "%"REG_c, "memory"
);
return bit & 1;
@@ -105,8 +112,8 @@ static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
{
x86_reg tmp;
__asm__ volatile(
- "movl %4, %k1 \n\t"
- "movl %2, %%eax \n\t"
+ "movl %a3(%2), %k1 \n\t"
+ "movl %a4(%2), %%eax \n\t"
"shl $17, %k1 \n\t"
"add %%eax, %%eax \n\t"
"sub %k1, %%eax \n\t"
@@ -117,20 +124,22 @@ static av_always_inline int get_cabac_bypass_sign_x86(CABACContext *c, int val)
"sub %%edx, %%ecx \n\t"
"test %%ax, %%ax \n\t"
" jnz 1f \n\t"
- "mov %3, %1 \n\t"
+ "mov %a5(%2), %1 \n\t"
"subl $0xFFFF, %%eax \n\t"
"movzwl (%1), %%edx \n\t"
"bswap %%edx \n\t"
"shrl $15, %%edx \n\t"
"add $2, %1 \n\t"
"addl %%edx, %%eax \n\t"
- "mov %1, %3 \n\t"
+ "mov %1, %a5(%2) \n\t"
"1: \n\t"
- "movl %%eax, %2 \n\t"
+ "movl %%eax, %a4(%2) \n\t"
- :"+c"(val), "=&r"(tmp), "+m"(c->low), "+m"(c->bytestream)
- :"m"(c->range)
- : "%eax", "%edx"
+ :"+c"(val), "=&r"(tmp)
+ :"r"(c),
+ "i"(offsetof(CABACContext, range)), "i"(offsetof(CABACContext, low)),
+ "i"(offsetof(CABACContext, bytestream))
+ : "%eax", "%edx", "memory"
);
return val;
}
diff --git a/libavcodec/x86/h264_i386.h b/libavcodec/x86/h264_i386.h
index 510f726ba10..84da48d2e2d 100644
--- a/libavcodec/x86/h264_i386.h
+++ b/libavcodec/x86/h264_i386.h
@@ -48,15 +48,15 @@ static int decode_significance_x86(CABACContext *c, int max_coeff,
__asm__ volatile(
"2: \n\t"
- BRANCHLESS_GET_CABAC("%4", "(%1)", "%3",
- "%w3", "%5", "%k0", "%b0", "%6")
+ BRANCHLESS_GET_CABAC("%4", "%6", "(%1)", "%3",
+ "%w3", "%5", "%k0", "%b0", "%a11")
"test $1, %4 \n\t"
" jz 3f \n\t"
"add %10, %1 \n\t"
- BRANCHLESS_GET_CABAC("%4", "(%1)", "%3",
- "%w3", "%5", "%k0", "%b0", "%6")
+ BRANCHLESS_GET_CABAC("%4", "%6", "(%1)", "%3",
+ "%w3", "%5", "%k0", "%b0", "%a11")
"sub %10, %1 \n\t"
"mov %2, %0 \n\t"
@@ -81,9 +81,9 @@ static int decode_significance_x86(CABACContext *c, int max_coeff,
"add %9, %k0 \n\t"
"shr $2, %k0 \n\t"
:"=&q"(coeff_count), "+r"(significant_coeff_ctx_base), "+m"(index),
- "+&r"(c->low), "=&r"(bit), "+&r"(c->range),
- "+m"(c->bytestream)
- :"m"(minusstart), "m"(end), "m"(minusindex), "m"(last_off)
+ "+&r"(c->low), "=&r"(bit), "+&r"(c->range)
+ :"r"(c), "m"(minusstart), "m"(end), "m"(minusindex), "m"(last_off),
+ "i"(offsetof(CABACContext, bytestream))
: "%"REG_c, "memory"
);
return coeff_count;
@@ -105,8 +105,8 @@ static int decode_significance_8x8_x86(CABACContext *c,
"movzbl (%0, %6), %k6 \n\t"
"add %9, %6 \n\t"
- BRANCHLESS_GET_CABAC("%4", "(%6)", "%3",
- "%w3", "%5", "%k0", "%b0", "%7")
+ BRANCHLESS_GET_CABAC("%4", "%7", "(%6)", "%3",
+ "%w3", "%5", "%k0", "%b0", "%a12")
"mov %1, %k6 \n\t"
"test $1, %4 \n\t"
@@ -115,8 +115,8 @@ static int decode_significance_8x8_x86(CABACContext *c,
"movzbl "MANGLE(last_coeff_flag_offset_8x8)"(%k6), %k6\n\t"
"add %11, %6 \n\t"
- BRANCHLESS_GET_CABAC("%4", "(%6)", "%3",
- "%w3", "%5", "%k0", "%b0", "%7")
+ BRANCHLESS_GET_CABAC("%4", "%7", "(%6)", "%3",
+ "%w3", "%5", "%k0", "%b0", "%a12")
"mov %2, %0 \n\t"
"mov %1, %k6 \n\t"
@@ -138,8 +138,9 @@ static int decode_significance_8x8_x86(CABACContext *c,
"addl %8, %k0 \n\t"
"shr $2, %k0 \n\t"
:"=&q"(coeff_count),"+m"(last), "+m"(index), "+&r"(c->low), "=&r"(bit),
- "+&r"(c->range), "=&r"(state), "+m"(c->bytestream)
- :"m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off), "m"(last_coeff_ctx_base)
+ "+&r"(c->range), "=&r"(state)
+ :"r"(c), "m"(minusindex), "m"(significant_coeff_ctx_base), "m"(sig_off), "m"(last_coeff_ctx_base),
+ "i"(offsetof(CABACContext, bytestream))
: "%"REG_c, "memory"
);
return coeff_count;
--
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