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Modify GET_GOT macro for performance.

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GET_GOT was producing a zero length call.  This resulted in
pipeline flushes occuring when returing from the assembly
functions.  Masked on out of order cores, but evident on
Atom cores.

Change-Id: I8c375af313e8a169c77adbaf956693c0cfeb5ccd
This commit is contained in:
Fritz Koenig 2010-09-14 15:46:37 -07:00
parent 769f2424cc
commit 746439ef6c
1 changed files with 13 additions and 6 deletions
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19
vpx_ports/x86_abi_support.asm
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@ -90,7 +90,7 @@
%macro ALIGN_STACK 2
mov %2, rsp
and rsp, -%1
sub rsp, %1 - REG_SZ_BYTES
lea rsp, [rsp - (%1 - REG_SZ_BYTES)]
push %2
%endmacro
@ -105,7 +105,6 @@
%idefine XMMWORD
%idefine MMWORD
; PIC macros
;
%if ABI_IS_32BIT
@ -116,9 +115,13 @@
extern _GLOBAL_OFFSET_TABLE_
push %1
call %%get_got
%%sub_offset:
jmp %%exitGG
%%get_got:
pop %1
add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%get_got wrt ..gotpc
mov %1, [esp]
add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%sub_offset wrt ..gotpc
ret
%%exitGG:
%undef GLOBAL
%define GLOBAL + %1 wrt ..gotoff
%undef RESTORE_GOT
@ -128,9 +131,13 @@
%macro GET_GOT 1
push %1
call %%get_got
%%sub_offset:
jmp %%exitGG
%%get_got:
pop %1
add %1, fake_got - %%get_got
mov %1, [esp]
add %1, fake_got - %%sub_offset
ret
%%exitGG:
%undef GLOBAL
%define GLOBAL + %1 - fake_got
%undef RESTORE_GOT