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Use .byte substitutes for ldmxcsr and stmxcsr instructions

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if OLD_ASSEMBLER macro is defined.

  Do not use PIC code for fpc_exp_real if OLD_ASSEMBLER is defined
  (this generates unsupported relocations for GNU assembler 2.6 used by EMX)

git-svn-id: trunk@37009 -
This commit is contained in:
pierre 2017-08-21 13:29:29 +00:00
parent df7946a9cc
commit d1e091d5a3
1 changed files with 53 additions and 1 deletions
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54
rtl/i386/math.inc
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@ -71,9 +71,22 @@ const
procedure SetMXCSR(w : dword);
begin
defaultmxcsr:=w;
{$ifndef OLD_ASSEMBLER}
asm
ldmxcsr w
end;
{$else}
{ Use convoluted code to avoid relocation on
ldmxcsr opcode, and use .byte version }
asm
mov w,%eax
subl $4,%esp
mov %eax,(%esp)
//ldmxcsr (%esp)
.byte 0x0f,0xae,0x14,0x24
addl $4,%esp
end;
{$endif OLD_ASSEMBLER}
end;
@ -81,9 +94,22 @@ const
var
_w : dword;
begin
{$ifndef OLD_ASSEMBLER}
asm
stmxcsr _w
end;
{$else}
asm
{ Use convoluted code to avoid relocation on
ldmxcsr opcode, and use .byte version }
subl $4,%esp
//stmxcsr (%esp)
.byte 0x0f,0xae,0x14,0x24
mov (%esp),%eax
addl $4,%esp
mov %eax,_w
end;
{$endif OLD_ASSEMBLER}
result:=_w;
end;
@ -152,6 +178,10 @@ const
result:=0;
end;
{$ifdef OLD_ASSEMBLER}
{$define DISABLE_PIC_IN_EXP_REAL}
{$endif}
{$define FPC_SYSTEM_HAS_EXP}
{ exp function adapted from AMath library (C) Copyright 2009-2013 Wolfgang Ehrhardt
* translated into AT&T syntax
@ -165,18 +195,28 @@ const
two: single=2.0;
half: single=0.5;
asm
{$ifndef DISABLE_PIC_IN_EXP_REAL}
call .LPIC
.LPIC:
pop %ecx
{$endif not DISABLE_PIC_IN_EXP_REAL}
fldt d
fldl2e
fmul %st(1),%st { z = d * log2(e) }
frndint
{ Calculate frac(z) using modular arithmetic to avoid precision loss. }
{$ifndef DISABLE_PIC_IN_EXP_REAL}
fldl ln2hi-.LPIC(%ecx)
{$else}
fldl ln2hi
{$endif}
fmul %st(1),%st
fsubrp %st,%st(2)
{$ifndef DISABLE_PIC_IN_EXP_REAL}
fldl ln2lo-.LPIC(%ecx)
{$else}
fldl ln2lo
{$endif}
fmul %st(1),%st
fsubrp %st,%st(2)
fxch %st(1) { (d-int(z)*ln2_hi)-int(z)*ln2_lo }
@ -196,7 +236,11 @@ const
jae .L1 { frac(z) <= 1 }
fld %st(1)
fabs
{$ifndef DISABLE_PIC_IN_EXP_REAL}
fcomps large-.LPIC(%ecx)
{$else}
fcomps large
{$endif}
fstsw %ax
sahf
jb .L0 { int(z) < 24576 }
@ -206,10 +250,18 @@ const
jmp .L1
.L0:
{ Calculate 2**frac(z)-1 as N*(N+2), where N=2**(frac(z)/2)-1 }
{$ifndef DISABLE_PIC_IN_EXP_REAL}
fmuls half-.LPIC(%ecx)
{$else}
fmuls half
{$endif}
f2xm1
fld %st
{$ifndef DISABLE_PIC_IN_EXP_REAL}
fadds two-.LPIC(%ecx)
{$else}
fadds two
{$endif}
fmulp %st,%st(1)
jmp .L2
.L1:
@ -289,6 +341,6 @@ const
movl res,%eax
movl res+4,%edx
end;