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-fix an obvious mistake in fpcw check

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-replace ARG_DOUBLE_ONE_HALF by _MSW/_LSW because this reflects the
 intention and also matches the terms used in C code,
 also make the code where the fpcw overwrites the argument a bit
 self-documenting
 (this abstraction sucks because it forces to write inefficient code)
This commit is contained in:
drochner 2008-06-23 10:24:13 +00:00
parent 7a21650601
commit bc43bac5ca
2 changed files with 18 additions and 16 deletions
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10
lib/libm/arch/i387/abi.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: abi.h,v 1.4 2008/06/23 00:14:46 christos Exp $ */
/* $NetBSD: abi.h,v 1.5 2008/06/23 10:24:13 drochner Exp $ */
/*
* Written by Frank van der Linden (fvdl@wasabisystems.com)
@ -16,9 +16,9 @@
#ifdef __x86_64__
#define ARG_DOUBLE_ONE_HALF -4(%rsp)
#define ARG_DOUBLE_ONE -8(%rsp)
#define ARG_DOUBLE_TWO_HALF -12(%rsp)
#define ARG_DOUBLE_ONE_LSW -8(%rsp)
#define ARG_DOUBLE_ONE_MSW -4(%rsp)
#define ARG_DOUBLE_TWO -16(%rsp)
#define ARG_FLOAT_ONE -4(%rsp)
#define ARG_FLOAT_TWO -8(%rsp)
@ -50,9 +50,9 @@
#else
#define ARG_DOUBLE_ONE 4(%esp)
#define ARG_DOUBLE_ONE_HALF 8(%esp)
#define ARG_DOUBLE_ONE_LSW 4(%esp)
#define ARG_DOUBLE_ONE_MSW 8(%esp)
#define ARG_DOUBLE_TWO 12(%esp)
#define ARG_DOUBLE_TWO_HALF 16(%esp)
#define ARG_FLOAT_ONE 4(%esp)
#define ARG_FLOAT_TWO 8(%esp)

24
lib/libm/arch/i387/e_exp.S
View File

@ -1,4 +1,4 @@
/* $NetBSD: e_exp.S,v 1.13 2008/06/23 00:12:04 christos Exp $ */
/* $NetBSD: e_exp.S,v 1.14 2008/06/23 10:24:13 drochner Exp $ */
/*
* Copyright (c) 1993,94 Winning Strategies, Inc.
@ -39,7 +39,7 @@
#include "abi.h"
RCSID("$NetBSD: e_exp.S,v 1.13 2008/06/23 00:12:04 christos Exp $")
RCSID("$NetBSD: e_exp.S,v 1.14 2008/06/23 10:24:13 drochner Exp $")
#if 0
RCSID("$FreeBSD: src/lib/msun/i387/e_exp.S,v 1.8.2.1 2000/07/10 09:16:28 obrien Exp $")
#endif
@ -51,7 +51,7 @@ ENTRY(__ieee754_exp)
* If x is +-Inf, then the subtraction would give Inf-Inf = NaN.
* Avoid this. Also avoid it if x is NaN for convenience.
*/
movl ARG_DOUBLE_ONE_HALF, %eax
movl ARG_DOUBLE_ONE_MSW, %eax
andl $0x7fffffff, %eax
cmpl $0x7ff00000, %eax
jae x_Inf_or_NaN
@ -63,13 +63,15 @@ ENTRY(__ieee754_exp)
* possible fraction) and that the precision is as high as possible.
* We may as well mask interrupts if we switch the mode.
*/
fstcw ARG_DOUBLE_ONE
movl ARG_DOUBLE_ONE, %eax
andl $0x0300, %eax
#define CWSTORE_SAV ARG_DOUBLE_ONE_LSW /* XXX overwrites the argument */
#define CWSTORE_TMP ARG_DOUBLE_ONE_MSW
fstcw CWSTORE_SAV
movl CWSTORE_SAV, %eax
andl $0x0f00, %eax
cmpl $0x0300, %eax /* RC == 0 && PC == 3? */
je 1f /* jump if mode is good */
movl $0x137f, ARG_DOUBLE_ONE_HALF
fldcw ARG_DOUBLE_ONE_HALF
movl $0x137f, CWSTORE_TMP
fldcw CWSTORE_TMP
1:
fldl2e
fmulp /* x * log2(e) */
@ -83,7 +85,7 @@ ENTRY(__ieee754_exp)
fscale /* e^x */
fstp %st(1)
je 1f
fldcw ARG_DOUBLE_ONE
fldcw CWSTORE_SAV
1:
XMM_DOUBLE_EPILOGUE
ret
@ -92,9 +94,9 @@ x_Inf_or_NaN:
* Return 0 if x is -Inf. Otherwise just return x, although the
* C version would return (x + x) (Real Indefinite) if x is a NaN.
*/
cmpl $0xfff00000, ARG_DOUBLE_ONE_HALF
cmpl $0xfff00000, ARG_DOUBLE_ONE_MSW
jne x_not_minus_Inf
cmpl $0, ARG_DOUBLE_ONE
cmpl $0, ARG_DOUBLE_ONE_LSW
jne x_not_minus_Inf
fldz
XMM_DOUBLE_EPILOGUE