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authorThilo Schulz <arny@ats.s.bawue.de>2011-09-27 14:43:20 +0000
committerTim Angus <tim@ngus.net>2013-01-10 23:38:28 +0000
commit36154934f5c0472b324f9054bee95af4b9bd94a7 (patch)
tree428bd45d0ad764da6c5f7e0a749601ded3d02cd0 /src/asm
parented1e20af481fd6fdb5dc8d1dc025586e4bf59129 (diff)
Set default rounding mode to FE_NEAREST again. Thanks to Matthias Bentrup for providing some explanations.
Diffstat (limited to 'src/asm')
-rw-r--r--src/asm/ftola.asm23
-rw-r--r--src/asm/ftola.c13
-rw-r--r--src/asm/snapvector.asm20
-rw-r--r--src/asm/snapvector.c29
4 files changed, 30 insertions, 55 deletions
diff --git a/src/asm/ftola.asm b/src/asm/ftola.asm
index 370c12d8..eea9d0e3 100644
--- a/src/asm/ftola.asm
+++ b/src/asm/ftola.asm
@@ -25,11 +25,11 @@ IFNDEF idx64
.model flat, c
ENDIF
-; .data
+.data
-; ifndef idx64
-; fpucw WORD 0F7Fh
-; endif
+ifndef idx64
+ fpucw WORD 0F7Fh
+endif
.code
@@ -51,22 +51,19 @@ ELSE
; qftol using FPU
qftolx87m macro src
-; not necessary, fpucw is set with _controlfp at startup
-; sub esp, 2
-; fnstcw word ptr [esp]
-; fldcw fpucw
+ sub esp, 2
+ fnstcw word ptr [esp]
+ fldcw fpucw
fld dword ptr src
fistp dword ptr src
-; fldcw [esp]
+ fldcw [esp]
mov eax, src
-; add esp, 2
+ add esp, 2
ret
endm
qftolx87 PROC
-; need this line when storing FPU control word on stack
-; qftolx87m [esp + 6]
- qftolx87m [esp + 4]
+ qftolx87m [esp + 6]
qftolx87 ENDP
qvmftolx87 PROC
diff --git a/src/asm/ftola.c b/src/asm/ftola.c
index ad197836..a2a4eaa0 100644
--- a/src/asm/ftola.c
+++ b/src/asm/ftola.c
@@ -22,6 +22,8 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#include "qasm-inline.h"
+static const unsigned short fpucw = 0x0C7F;
+
/*
* GNU inline asm ftol conversion functions using SSE or FPU
*/
@@ -59,14 +61,18 @@ int qvmftolsse(void)
long qftolx87(float f)
{
long retval;
+ unsigned short oldcw;
__asm__ volatile
(
+ "fnstcw %2\n"
+ "fldcw %3\n"
"flds %1\n"
"fistpl %1\n"
+ "fldcw %2\n"
"mov %1, %0\n"
: "=r" (retval)
- : "m" (f)
+ : "m" (f), "m" (oldcw), "m" (fpucw)
);
return retval;
@@ -75,13 +81,18 @@ long qftolx87(float f)
int qvmftolx87(void)
{
int retval;
+ unsigned short oldcw;
__asm__ volatile
(
+ "fnstcw %1\n"
+ "fldcw %2\n"
"flds (" EDI ", " EBX ", 4)\n"
"fistpl (" EDI ", " EBX ", 4)\n"
+ "fldcw %2\n"
"mov (" EDI ", " EBX ", 4), %0\n"
: "=r" (retval)
+ : "m" (oldcw), "m" (fpucw)
);
return retval;
diff --git a/src/asm/snapvector.asm b/src/asm/snapvector.asm
index 000777b4..22f9b225 100644
--- a/src/asm/snapvector.asm
+++ b/src/asm/snapvector.asm
@@ -45,9 +45,6 @@ IFDEF idx64
qsnapvectorsse PROC
sub rsp, 8
- stmxcsr [rsp] ; save SSE control word
- ldmxcsr ssecw ; set to round nearest
-
movaps xmm1, ssemask ; initialize the mask register
movups xmm0, [rcx] ; here is stored our vector. Read 4 values in one go
movaps xmm2, xmm0 ; keep a copy of the original data
@@ -57,20 +54,13 @@ IFDEF idx64
cvtdq2ps xmm0, xmm0 ; convert 4 int to single fp
orps xmm0, xmm1 ; combine all 4 values again
movups [rcx], xmm0 ; write 3 rounded and 1 unchanged values back to memory
-
- ldmxcsr [rsp] ; restore sse control word to old value
- add rsp, 8
ret
qsnapvectorsse ENDP
ELSE
qsnapvectorsse PROC
- sub esp, 8
- stmxcsr [esp] ; save SSE control word
- ldmxcsr ssecw ; set to round nearest
-
- mov eax, dword ptr 12[esp] ; store address of vector in eax
+ mov eax, dword ptr 4[esp] ; store address of vector in eax
movaps xmm1, ssemask ; initialize the mask register for maskmovdqu
movups xmm0, [eax] ; here is stored our vector. Read 4 values in one go
movaps xmm2, xmm0 ; keep a copy of the original data
@@ -80,9 +70,6 @@ ELSE
cvtdq2ps xmm0, xmm0 ; convert 4 int to single fp
orps xmm0, xmm1 ; combine all 4 values again
movups [eax], xmm0 ; write 3 rounded and 1 unchanged values back to memory
-
- ldmxcsr [esp] ; restore sse control word to old value
- add esp, 8
ret
qsnapvectorsse ENDP
@@ -95,14 +82,9 @@ ELSE
qsnapvectorx87 PROC
mov eax, dword ptr 4[esp]
- sub esp, 2
- fnstcw word ptr [esp]
- fldcw fpucw
qroundx87 [eax]
qroundx87 4[eax]
qroundx87 8[eax]
- fldcw [esp]
- add esp, 2
ret
qsnapvectorx87 ENDP
diff --git a/src/asm/snapvector.c b/src/asm/snapvector.c
index 121c110e..a70a1069 100644
--- a/src/asm/snapvector.c
+++ b/src/asm/snapvector.c
@@ -33,31 +33,21 @@ static unsigned char ssemask[16] __attribute__((aligned(16))) =
"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\x00\x00\x00\x00"
};
-static const unsigned int ssecw __attribute__((aligned(16))) = 0x00001F80;
-static const unsigned short fpucw = 0x037F;
-
void qsnapvectorsse(vec3_t vec)
{
- uint32_t oldcw __attribute__((aligned(16)));
-
__asm__ volatile
(
- "stmxcsr %3\n"
- "ldmxcsr %1\n"
-
"movaps (%0), %%xmm1\n"
- "movups (%2), %%xmm0\n"
+ "movups (%1), %%xmm0\n"
"movaps %%xmm0, %%xmm2\n"
"andps %%xmm1, %%xmm0\n"
"andnps %%xmm2, %%xmm1\n"
"cvtps2dq %%xmm0, %%xmm0\n"
"cvtdq2ps %%xmm0, %%xmm0\n"
"orps %%xmm1, %%xmm0\n"
- "movups %%xmm0, (%2)\n"
-
- "ldmxcsr %3\n"
+ "movups %%xmm0, (%1)\n"
:
- : "r" (ssemask), "m" (ssecw), "r" (vec), "m" (oldcw)
+ : "r" (ssemask), "r" (vec)
: "memory", "%xmm0", "%xmm1", "%xmm2"
);
@@ -73,16 +63,11 @@ void qsnapvectorx87(vec3_t vec)
{
__asm__ volatile
(
- "sub $2, " ESP "\n"
- "fnstcw (" ESP ")\n"
- "fldcw %0\n"
- QROUNDX87("(%1)")
- QROUNDX87("4(%1)")
- QROUNDX87("8(%1)")
- "fldcw (" ESP ")\n"
- "add $2, " ESP "\n"
+ QROUNDX87("(%0)")
+ QROUNDX87("4(%0)")
+ QROUNDX87("8(%0)")
:
- : "m" (fpucw), "r" (vec)
+ : "r" (vec)
: "memory"
);
}