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tm.texi.in (TARGET_HAS_NO_HW_DIVIDE): Define.

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2013-11-27  Kugan Vivekanandarajah  <kuganv@linaro.org>

	gcc/
	* doc/tm.texi.in (TARGET_HAS_NO_HW_DIVIDE): Define.
	* doc/tm.texi (TARGET_HAS_NO_HW_DIVIDE): Regenerate.

	libgcc/
	* libgcc2.c (__udivmoddi4): Define new implementation when
	TARGET_HAS_NO_HW_DIVIDE is defined, for processors without any
	divide instructions.

From-SVN: r205444
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Kugan Vivekanandarajah 2013-11-27 12:17:05 +00:00 committed by Christophe Lyon
parent 536da97c4e
commit 30b8f78b72
5 changed files with 96 additions and 0 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2013-11-27 Kugan Vivekanandarajah <kuganv@linaro.org>
* doc/tm.texi.in (TARGET_HAS_NO_HW_DIVIDE): Define.
* doc/tm.texi (TARGET_HAS_NO_HW_DIVIDE): Regenerate.
2013-11-27 Marek Polacek <polacek@redhat.com>
PR sanitizer/59306

8
gcc/doc/tm.texi
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@ -5365,6 +5365,14 @@ If this macro evaluates to @code{false} the comparison functions return
in @file{libgcc.a}, you do not need to define this macro.
@end defmac
@defmac TARGET_HAS_NO_HW_DIVIDE
This macro should be defined if the target has no hardware divide
instructions. If this macro is defined, GCC will use an algorithm which
make use of simple logical and arithmetic operations for 64-bit
division. If the macro is not defined, GCC will use an algorithm which
make use of a 64-bit by 32-bit divide primitive.
@end defmac
@cindex @code{EDOM}, implicit usage
@findex matherr
@defmac TARGET_EDOM

8
gcc/doc/tm.texi.in
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@ -4205,6 +4205,14 @@ If this macro evaluates to @code{false} the comparison functions return
in @file{libgcc.a}, you do not need to define this macro.
@end defmac
@defmac TARGET_HAS_NO_HW_DIVIDE
This macro should be defined if the target has no hardware divide
instructions. If this macro is defined, GCC will use an algorithm which
make use of simple logical and arithmetic operations for 64-bit
division. If the macro is not defined, GCC will use an algorithm which
make use of a 64-bit by 32-bit divide primitive.
@end defmac
@cindex @code{EDOM}, implicit usage
@findex matherr
@defmac TARGET_EDOM

6
libgcc/ChangeLog
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@ -1,3 +1,9 @@
2013-11-27 Kugan Vivekanandarajah <kuganv@linaro.org>
* libgcc2.c (__udivmoddi4): Define new implementation when
TARGET_HAS_NO_HW_DIVIDE is defined, for processors without any
divide instructions.
2013-11-25 Oleg Endo <olegendo@gcc.gnu.org>
* config/sh/crt1.S (start): Don't do VBR_SETUP for SH2E.

69
libgcc/libgcc2.c
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@ -934,6 +934,74 @@ __parityDI2 (UDWtype x)
#endif
#ifdef L_udivmoddi4
#ifdef TARGET_HAS_NO_HW_DIVIDE
#if (defined (L_udivdi3) || defined (L_divdi3) || \
defined (L_umoddi3) || defined (L_moddi3))
static inline __attribute__ ((__always_inline__))
#endif
UDWtype
__udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp)
{
UDWtype q = 0, r = n, y = d;
UWtype lz1, lz2, i, k;
/* Implements align divisor shift dividend method. This algorithm
aligns the divisor under the dividend and then perform number of
test-subtract iterations which shift the dividend left. Number of
iterations is k + 1 where k is the number of bit positions the
divisor must be shifted left to align it under the dividend.
quotient bits can be saved in the rightmost positions of the dividend
as it shifts left on each test-subtract iteration. */
if (y <= r)
{
lz1 = __builtin_clzll (d);
lz2 = __builtin_clzll (n);
k = lz1 - lz2;
y = (y << k);
/* Dividend can exceed 2 ^ (width − 1) − 1 but still be less than the
aligned divisor. Normal iteration can drops the high order bit
of the dividend. Therefore, first test-subtract iteration is a
special case, saving its quotient bit in a separate location and
not shifting the dividend. */
if (r >= y)
{
r = r - y;
q = (1ULL << k);
}
if (k > 0)
{
y = y >> 1;
/* k additional iterations where k regular test subtract shift
dividend iterations are done. */
i = k;
do
{
if (r >= y)
r = ((r - y) << 1) + 1;
else
r = (r << 1);
i = i - 1;
} while (i != 0);
/* First quotient bit is combined with the quotient bits resulting
from the k regular iterations. */
q = q + r;
r = r >> k;
q = q - (r << k);
}
}
if (rp)
*rp = r;
return q;
}
#else
#if (defined (L_udivdi3) || defined (L_divdi3) || \
defined (L_umoddi3) || defined (L_moddi3))
@ -1152,6 +1220,7 @@ __udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp)
return ww.ll;
}
#endif
#endif
#ifdef L_divdi3
DWtype