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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 filename
5589802 612739 3833856 10036397 9924ad vmlinux.before
5589802 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>
116 lines
3.9 KiB
C
116 lines
3.9 KiB
C
/*---------------------------------------------------------------------------+
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| reg_mul.c |
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| Multiply one FPU_REG by another, put the result in a destination FPU_REG. |
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| Copyright (C) 1992,1993,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
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| E-mail billm@suburbia.net |
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| Returns the tag of the result if no exceptions or errors occurred. |
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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 "fpu_emu.h"
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#include "exception.h"
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#include "reg_constant.h"
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#include "fpu_system.h"
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/*
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Multiply two registers to give a register result.
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The sources are st(deststnr) and (b,tagb,signb).
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The destination is st(deststnr).
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*/
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/* This routine must be called with non-empty source registers */
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int FPU_mul(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
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{
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FPU_REG *a = &st(deststnr);
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FPU_REG *dest = a;
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u_char taga = FPU_gettagi(deststnr);
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u_char saved_sign = getsign(dest);
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u_char sign = (getsign(a) ^ getsign(b));
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int tag;
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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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tag =
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FPU_u_mul(a, b, dest, control_w, sign,
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exponent(a) + exponent(b));
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if (tag < 0) {
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setsign(dest, saved_sign);
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return tag;
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}
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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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FPU_REG x, y;
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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_mul(&x, &y, dest, control_w, sign,
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exponent16(&x) + exponent16(&y));
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if (tag < 0) {
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setsign(dest, saved_sign);
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return tag;
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}
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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 == TW_Denormal) || (taga == TW_Denormal))
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&& (denormal_operand() < 0))
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return FPU_Exception;
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/* Must have either both arguments == zero, or
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one valid and the other zero.
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The result is therefore zero. */
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FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
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/* The 80486 book says that the answer is +0, but a real
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80486 behaves this way.
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IEEE-754 apparently says it should be this way. */
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setsign(dest, sign);
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return TAG_Zero;
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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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return real_2op_NaN(b, tagb, deststnr, &st(0));
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} else if (((taga == TW_Infinity) && (tagb == TAG_Zero))
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|| ((tagb == TW_Infinity) && (taga == TAG_Zero))) {
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return arith_invalid(deststnr); /* Zero*Infinity is invalid */
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} else if (((taga == TW_Denormal) || (tagb == TW_Denormal))
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&& (denormal_operand() < 0)) {
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return FPU_Exception;
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} else if (taga == TW_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 TAG_Special;
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} else if (tagb == TW_Infinity) {
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FPU_copy_to_regi(b, TAG_Special, deststnr);
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setsign(dest, sign);
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return TAG_Special;
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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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