From: Henrik Gramner Date: Sun, 9 Feb 2014 22:58:04 +0000 (+0100) Subject: x86inc: Support arbitrary stack alignments X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=7c860f075ccd14fb7891d5fc6c9eab1a37ea555d;p=x264 x86inc: Support arbitrary stack alignments If the stack is known to be at least 32-byte aligned we can safely store ymm registers on the stack without doing manual alignment. Change ALLOC_STACK to always align the stack before allocating stack space for consistency. Previously alignment would occur either before or after allocating stack space depending on whether manual alignment was required or not. --- diff --git a/common/cpu.c b/common/cpu.c index 39d114cc..d5502ece 100644 --- a/common/cpu.c +++ b/common/cpu.c @@ -304,7 +304,7 @@ uint32_t x264_cpu_detect( void ) x264_log( NULL, X264_LOG_WARNING, "unable to determine cacheline size\n" ); } -#if BROKEN_STACK_ALIGNMENT +#if STACK_ALIGNMENT < 16 cpu |= X264_CPU_STACK_MOD4; #endif diff --git a/common/cpu.h b/common/cpu.h index 3c10cd22..6d08027a 100644 --- a/common/cpu.h +++ b/common/cpu.h @@ -57,7 +57,7 @@ void x264_safe_intel_cpu_indicator_init( void ); * alignment between functions (osdep.h handles manual alignment of arrays * if it doesn't). */ -#if (ARCH_X86 || HAVE_32B_STACK_ALIGNMENT) && HAVE_MMX +#if (ARCH_X86 || STACK_ALIGNMENT > 16) && HAVE_MMX intptr_t x264_stack_align( void (*func)(), ... ); #define x264_stack_align(func,...) x264_stack_align((void (*)())func, __VA_ARGS__) #else diff --git a/common/osdep.h b/common/osdep.h index 28a2e85f..f2bd39ca 100644 --- a/common/osdep.h +++ b/common/osdep.h @@ -126,7 +126,7 @@ int x264_is_pipe( const char *path ); #define EXPAND(x) x -#if HAVE_32B_STACK_ALIGNMENT +#if STACK_ALIGNMENT >= 32 #define ALIGNED_ARRAY_32( type, name, sub1, ... )\ ALIGNED_32( type name sub1 __VA_ARGS__ ) #else diff --git a/common/x86/deblock-a.asm b/common/x86/deblock-a.asm index 4dcbeddd..0b61869b 100644 --- a/common/x86/deblock-a.asm +++ b/common/x86/deblock-a.asm @@ -1392,19 +1392,18 @@ cglobal deblock_%1_luma, 5,5,8,2*%2 ;----------------------------------------------------------------------------- ; void deblock_h_luma( uint8_t *pix, intptr_t stride, int alpha, int beta, int8_t *tc0 ) ;----------------------------------------------------------------------------- - %if cpuflag(avx) INIT_XMM cpuname %else INIT_MMX cpuname %endif -cglobal deblock_h_luma, 0,5,8,0x60+HAVE_ALIGNED_STACK*12 - mov r0, r0mp +cglobal deblock_h_luma, 1,5,8,0x60+12 mov r3, r1m lea r4, [r3*3] sub r0, 4 lea r1, [r0+r4] - %define pix_tmp esp+12*HAVE_ALIGNED_STACK + %define pix_tmp esp+12 + ; esp is intentionally misaligned to make it aligned after pushing the arguments for deblock_%1_luma. ; transpose 6x16 -> tmp space TRANSPOSE6x8_MEM PASS8ROWS(r0, r1, r3, r4), pix_tmp diff --git a/common/x86/x86inc.asm b/common/x86/x86inc.asm index 7713bfa1..bfbfef15 100644 --- a/common/x86/x86inc.asm +++ b/common/x86/x86inc.asm @@ -42,6 +42,14 @@ %define public_prefix private_prefix %endif +%ifndef STACK_ALIGNMENT + %if ARCH_X86_64 + %define STACK_ALIGNMENT 16 + %else + %define STACK_ALIGNMENT 4 + %endif +%endif + %define WIN64 0 %define UNIX64 0 %if ARCH_X86_64 @@ -94,8 +102,9 @@ CPU amdnop ; %1 = number of arguments. loads them from stack if needed. ; %2 = number of registers used. pushes callee-saved regs if needed. ; %3 = number of xmm registers used. pushes callee-saved xmm regs if needed. -; %4 = (optional) stack size to be allocated. If not aligned (x86-32 ICC 10.x, -; MSVC or YMM), the stack will be manually aligned (to 16 or 32 bytes), +; %4 = (optional) stack size to be allocated. The stack will be aligned before +; allocating the specified stack size. If the required stack alignment is +; larger than the known stack alignment the stack will be manually aligned ; and an extra register will be allocated to hold the original stack ; pointer (to not invalidate r0m etc.). To prevent the use of an extra ; register as stack pointer, request a negative stack size. @@ -103,8 +112,10 @@ CPU amdnop ; PROLOGUE can also be invoked by adding the same options to cglobal ; e.g. -; cglobal foo, 2,3,0, dst, src, tmp -; declares a function (foo), taking two args (dst and src) and one local variable (tmp) +; cglobal foo, 2,3,7,0x40, dst, src, tmp +; declares a function (foo) that automatically loads two arguments (dst and +; src) into registers, uses one additional register (tmp) plus 7 vector +; registers (m0-m6) and allocates 0x40 bytes of stack space. ; TODO Some functions can use some args directly from the stack. If they're the ; last args then you can just not declare them, but if they're in the middle @@ -304,26 +315,28 @@ DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14 %assign n_arg_names %0 %endmacro +%define required_stack_alignment ((mmsize + 15) & ~15) + %macro ALLOC_STACK 1-2 0 ; stack_size, n_xmm_regs (for win64 only) %ifnum %1 %if %1 != 0 - %assign %%stack_alignment ((mmsize + 15) & ~15) + %assign %%pad 0 %assign stack_size %1 %if stack_size < 0 %assign stack_size -stack_size %endif - %assign stack_size_padded stack_size %if WIN64 - %assign stack_size_padded stack_size_padded + 32 ; reserve 32 bytes for shadow space + %assign %%pad %%pad + 32 ; shadow space %if mmsize != 8 %assign xmm_regs_used %2 %if xmm_regs_used > 8 - %assign stack_size_padded stack_size_padded + (xmm_regs_used-8)*16 + %assign %%pad %%pad + (xmm_regs_used-8)*16 ; callee-saved xmm registers %endif %endif %endif - %if mmsize <= 16 && HAVE_ALIGNED_STACK - %assign stack_size_padded stack_size_padded + %%stack_alignment - gprsize - (stack_offset & (%%stack_alignment - 1)) + %if required_stack_alignment <= STACK_ALIGNMENT + ; maintain the current stack alignment + %assign stack_size_padded stack_size + %%pad + ((-%%pad-stack_offset-gprsize) & (STACK_ALIGNMENT-1)) SUB rsp, stack_size_padded %else %assign %%reg_num (regs_used - 1) @@ -332,17 +345,17 @@ DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14 ; it, i.e. in [rsp+stack_size_padded], so we can restore the ; stack in a single instruction (i.e. mov rsp, rstk or mov ; rsp, [rsp+stack_size_padded]) - mov rstk, rsp %if %1 < 0 ; need to store rsp on stack - sub rsp, gprsize+stack_size_padded - and rsp, ~(%%stack_alignment-1) - %xdefine rstkm [rsp+stack_size_padded] - mov rstkm, rstk + %xdefine rstkm [rsp + stack_size + %%pad] + %assign %%pad %%pad + gprsize %else ; can keep rsp in rstk during whole function - sub rsp, stack_size_padded - and rsp, ~(%%stack_alignment-1) %xdefine rstkm rstk %endif + %assign stack_size_padded stack_size + ((%%pad + required_stack_alignment-1) & ~(required_stack_alignment-1)) + mov rstk, rsp + and rsp, ~(required_stack_alignment-1) + sub rsp, stack_size_padded + movifnidn rstkm, rstk %endif WIN64_PUSH_XMM %endif @@ -351,7 +364,7 @@ DECLARE_REG_TMP_SIZE 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14 %macro SETUP_STACK_POINTER 1 %ifnum %1 - %if %1 != 0 && (HAVE_ALIGNED_STACK == 0 || mmsize == 32) + %if %1 != 0 && required_stack_alignment > STACK_ALIGNMENT %if %1 > 0 %assign regs_used (regs_used + 1) %elif ARCH_X86_64 && regs_used == num_args && num_args <= 4 + UNIX64 * 2 @@ -425,7 +438,9 @@ DECLARE_REG 14, R15, 120 %assign xmm_regs_used %1 ASSERT xmm_regs_used <= 16 %if xmm_regs_used > 8 - %assign stack_size_padded (xmm_regs_used-8)*16 + (~stack_offset&8) + 32 + ; Allocate stack space for callee-saved xmm registers plus shadow space and align the stack. + %assign %%pad (xmm_regs_used-8)*16 + 32 + %assign stack_size_padded %%pad + ((-%%pad-stack_offset-gprsize) & (STACK_ALIGNMENT-1)) SUB rsp, stack_size_padded %endif WIN64_PUSH_XMM @@ -441,7 +456,7 @@ DECLARE_REG 14, R15, 120 %endrep %endif %if stack_size_padded > 0 - %if stack_size > 0 && (mmsize == 32 || HAVE_ALIGNED_STACK == 0) + %if stack_size > 0 && required_stack_alignment > STACK_ALIGNMENT mov rsp, rstkm %else add %1, stack_size_padded @@ -507,7 +522,7 @@ DECLARE_REG 14, R15, 72 %macro RET 0 %if stack_size_padded > 0 -%if mmsize == 32 || HAVE_ALIGNED_STACK == 0 +%if required_stack_alignment > STACK_ALIGNMENT mov rsp, rstkm %else add rsp, stack_size_padded @@ -563,7 +578,7 @@ DECLARE_ARG 7, 8, 9, 10, 11, 12, 13, 14 %macro RET 0 %if stack_size_padded > 0 -%if mmsize == 32 || HAVE_ALIGNED_STACK == 0 +%if required_stack_alignment > STACK_ALIGNMENT mov rsp, rstkm %else add rsp, stack_size_padded diff --git a/configure b/configure index 74ce8968..54017534 100755 --- a/configure +++ b/configure @@ -557,7 +557,7 @@ esac LDFLAGS="$LDFLAGS $libm" -aligned_stack=1 +stack_alignment=16 case $host_cpu in i*86) ARCH="X86" @@ -577,8 +577,7 @@ case $host_cpu in if [ $SYS = LINUX ]; then # < 11 is completely incapable of keeping a mod16 stack if cpp_check "" "" "__INTEL_COMPILER < 1100" ; then - define BROKEN_STACK_ALIGNMENT - aligned_stack=0 + stack_alignment=4 # 11 <= x < 12 is capable of keeping a mod16 stack, but defaults to not doing so. elif cpp_check "" "" "__INTEL_COMPILER < 1200" ; then CFLAGS="$CFLAGS -falign-stack=assume-16-byte" @@ -586,7 +585,7 @@ case $host_cpu in # >= 12 defaults to a mod16 stack fi # icl on windows has no mod16 stack support - [ $SYS = WINDOWS ] && define BROKEN_STACK_ALIGNMENT && aligned_stack=0 + [ $SYS = WINDOWS ] && stack_alignment=4 fi if [ "$SYS" = MACOSX ]; then ASFLAGS="$ASFLAGS -f macho -DPREFIX" @@ -681,7 +680,6 @@ case $host_cpu in ARCH="$(echo $host_cpu | tr a-z A-Z)" ;; esac -ASFLAGS="$ASFLAGS -DHAVE_ALIGNED_STACK=${aligned_stack}" if [ $SYS = WINDOWS ]; then if ! rc_check "0 RCDATA {0}" ; then @@ -735,9 +733,9 @@ if [ $asm = auto -a \( $ARCH = X86 -o $ARCH = X86_64 \) ] ; then fi ASFLAGS="$ASFLAGS -Worphan-labels" define HAVE_MMX - if cc_check '' -mpreferred-stack-boundary=5 ; then + if [ $compiler = GNU ] && cc_check '' -mpreferred-stack-boundary=5 ; then CFLAGS="$CFLAGS -mpreferred-stack-boundary=5" - define HAVE_32B_STACK_ALIGNMENT + stack_alignment=32 fi fi @@ -762,6 +760,9 @@ fi define ARCH_$ARCH define SYS_$SYS +define STACK_ALIGNMENT $stack_alignment +ASFLAGS="$ASFLAGS -DSTACK_ALIGNMENT=$stack_alignment" + # skip endianness check for Intel Compiler, as all supported platforms are little. the -ipo flag will also cause the check to fail if [ $compiler = GNU ]; then echo "int i[2] = {0x42494745,0}; double f[2] = {0x1.0656e6469616ep+102,0};" > conftest.c diff --git a/tools/checkasm.c b/tools/checkasm.c index fd587da1..2a287747 100644 --- a/tools/checkasm.c +++ b/tools/checkasm.c @@ -2530,7 +2530,7 @@ static int add_flags( int *cpu_ref, int *cpu_new, int flags, const char *name ) { *cpu_ref = *cpu_new; *cpu_new |= flags; -#if BROKEN_STACK_ALIGNMENT +#if STACK_ALIGNMENT < 16 *cpu_new |= X264_CPU_STACK_MOD4; #endif if( *cpu_new & X264_CPU_SSE2_IS_FAST )