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3d0d14f983
lindent these files: errors lines of code errors/KLOC arch/x86/math-emu/ 2236 9424 237.2 arch/x86/math-emu/ 128 8706 14.7 no other changes. No code changed: text data bss dec hex filename5589802
612739 3833856 10036397 9924ad vmlinux.before5589802
612739 3833856 10036397 9924ad vmlinux.after the intent of this patch is to ease the automated tracking of kernel code quality - it's just much easier for us to maintain it if every file in arch/x86 is supposed to be clean. NOTE: it is a known problem of lindent that it causes some style damage of its own, but it's a safe tool (well, except for the gcc array range initializers extension), so we did the bulk of the changes via lindent, and did the manual fixups in a followup patch. the resulting math-emu code has been tested by Thomas Gleixner on a real 386 DX CPU as well, and it works fine. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
183 lines
4.9 KiB
C
183 lines
4.9 KiB
C
/*---------------------------------------------------------------------------+
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| reg_divide.c |
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| Divide one FPU_REG by another and put the result in a destination FPU_REG.|
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| Copyright (C) 1996 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
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| E-mail billm@jacobi.maths.monash.edu.au |
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| Return value is the tag of the answer, or-ed with FPU_Exception if |
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| one was raised, or -1 on internal error. |
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+---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------+
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| The destination may be any FPU_REG, including one of the source FPU_REGs. |
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+---------------------------------------------------------------------------*/
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#include "exception.h"
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#include "reg_constant.h"
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#include "fpu_emu.h"
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#include "fpu_system.h"
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/*
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Divide one register by another and put the result into a third register.
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*/
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int FPU_div(int flags, int rm, int control_w)
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{
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FPU_REG x, y;
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FPU_REG const *a, *b, *st0_ptr, *st_ptr;
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FPU_REG *dest;
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u_char taga, tagb, signa, signb, sign, saved_sign;
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int tag, deststnr;
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if (flags & DEST_RM)
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deststnr = rm;
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else
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deststnr = 0;
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if (flags & REV) {
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b = &st(0);
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st0_ptr = b;
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tagb = FPU_gettag0();
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if (flags & LOADED) {
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a = (FPU_REG *) rm;
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taga = flags & 0x0f;
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} else {
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a = &st(rm);
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st_ptr = a;
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taga = FPU_gettagi(rm);
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}
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} else {
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a = &st(0);
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st0_ptr = a;
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taga = FPU_gettag0();
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if (flags & LOADED) {
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b = (FPU_REG *) rm;
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tagb = flags & 0x0f;
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} else {
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b = &st(rm);
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st_ptr = b;
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tagb = FPU_gettagi(rm);
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}
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}
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signa = getsign(a);
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signb = getsign(b);
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sign = signa ^ signb;
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dest = &st(deststnr);
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saved_sign = getsign(dest);
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if (!(taga | tagb)) {
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/* Both regs Valid, this should be the most common case. */
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reg_copy(a, &x);
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reg_copy(b, &y);
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setpositive(&x);
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setpositive(&y);
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tag = FPU_u_div(&x, &y, dest, control_w, sign);
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if (tag < 0)
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return tag;
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FPU_settagi(deststnr, tag);
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return tag;
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}
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if (taga == TAG_Special)
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taga = FPU_Special(a);
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if (tagb == TAG_Special)
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tagb = FPU_Special(b);
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if (((taga == TAG_Valid) && (tagb == TW_Denormal))
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|| ((taga == TW_Denormal) && (tagb == TAG_Valid))
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|| ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
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if (denormal_operand() < 0)
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return FPU_Exception;
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FPU_to_exp16(a, &x);
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FPU_to_exp16(b, &y);
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tag = FPU_u_div(&x, &y, dest, control_w, sign);
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if (tag < 0)
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return tag;
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FPU_settagi(deststnr, tag);
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return tag;
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} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
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if (tagb != TAG_Zero) {
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/* Want to find Zero/Valid */
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if (tagb == TW_Denormal) {
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if (denormal_operand() < 0)
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return FPU_Exception;
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}
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/* The result is zero. */
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FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
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setsign(dest, sign);
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return TAG_Zero;
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}
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/* We have an exception condition, either 0/0 or Valid/Zero. */
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if (taga == TAG_Zero) {
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/* 0/0 */
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return arith_invalid(deststnr);
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}
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/* Valid/Zero */
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return FPU_divide_by_zero(deststnr, sign);
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}
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/* Must have infinities, NaNs, etc */
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else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
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if (flags & LOADED)
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return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0,
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st0_ptr);
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if (flags & DEST_RM) {
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int tag;
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tag = FPU_gettag0();
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if (tag == TAG_Special)
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tag = FPU_Special(st0_ptr);
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return real_2op_NaN(st0_ptr, tag, rm,
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(flags & REV) ? st0_ptr : &st(rm));
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} else {
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int tag;
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tag = FPU_gettagi(rm);
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if (tag == TAG_Special)
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tag = FPU_Special(&st(rm));
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return real_2op_NaN(&st(rm), tag, 0,
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(flags & REV) ? st0_ptr : &st(rm));
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}
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} else if (taga == TW_Infinity) {
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if (tagb == TW_Infinity) {
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/* infinity/infinity */
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return arith_invalid(deststnr);
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} else {
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/* tagb must be Valid or Zero */
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if ((tagb == TW_Denormal) && (denormal_operand() < 0))
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return FPU_Exception;
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/* Infinity divided by Zero or Valid does
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not raise and exception, but returns Infinity */
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FPU_copy_to_regi(a, TAG_Special, deststnr);
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setsign(dest, sign);
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return taga;
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}
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} else if (tagb == TW_Infinity) {
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if ((taga == TW_Denormal) && (denormal_operand() < 0))
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return FPU_Exception;
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/* The result is zero. */
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FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
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setsign(dest, sign);
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return TAG_Zero;
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}
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#ifdef PARANOID
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else {
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EXCEPTION(EX_INTERNAL | 0x102);
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return FPU_Exception;
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}
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#endif /* PARANOID */
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return 0;
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}
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