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[PATCH] general soft-fp fixes for PPC32 long-double
- From: Steven Munroe <munroesj at us dot ibm dot com>
- To: libc-alpha at sources dot redhat dot com, "Joseph S. Myers" <joseph at codesourcery dot com>, David Edelsohn <dje at watson dot ibm dot com>
- Date: Fri, 15 Sep 2006 18:05:02 -0500
- Subject: [PATCH] general soft-fp fixes for PPC32 long-double
The attached patch fixes generic soft-fp bugs found during the long
double testing (bugz 2749).
This fix is a pre-req for the gcc-4.2 powerpc soft-fp support but common
to all soft-fp implementations.
As I understand it we need the soft-fp into the glibc upstream before we
can propagate the fixes to gcc, before David can submit the rest of the
gcc soft-fp fixes for gcc-4.2. We are running out of time for gcc-4.2.
Thanks.
2006-08-30 Steven Munroe <sjmunroe@us.ibm.com>
Joe Kerian <jkerian@us.us.ibm.com>
[BZ #2749]
* soft-fp/op-common.h (_FP_OVERFLOW_SEMIRAW): Always set inexact
and overflow for infinity.
(_FP_PACK_SEMIRAW): Update comment. Do not round if NaN.
* soft-fp/op-4.h (__FP_FRAC_SUB_3, __FP_FRAC_SUB_4): Correct borrow
handling for high words.
diff -urN libc24-cvstip-20060830/soft-fp/op-4.h libc24-ppc64-20060830/soft-fp/op-4.h
--- libc24-cvstip-20060830/soft-fp/op-4.h 2006-04-04 03:24:47.000000000 -0500
+++ libc24-ppc64-20060830/soft-fp/op-4.h 2006-09-14 14:55:09.000000000 -0500
@@ -564,7 +564,7 @@
r1 = x1 - y1; \
_c2 = r1 > x1; \
r1 -= _c1; \
- _c2 |= r1 > _c1; \
+ _c2 |= _c1 && (y1 == x1); \
r2 = x2 - y2 - _c2; \
} while (0)
#endif
@@ -578,11 +578,11 @@
r1 = x1 - y1; \
_c2 = r1 > x1; \
r1 -= _c1; \
- _c2 |= r1 > _c1; \
+ _c2 |= _c1 && (y1 == x1); \
r2 = x2 - y2; \
_c3 = r2 > x2; \
r2 -= _c2; \
- _c3 |= r2 > _c2; \
+ _c3 |= _c2 && (y2 == x2); \
r3 = x3 - y3 - _c3; \
} while (0)
#endif
diff -urN libc24-cvstip-20060830/soft-fp/op-common.h libc24-ppc64-20060830/soft-fp/op-common.h
--- libc24-cvstip-20060830/soft-fp/op-common.h 2006-04-04 03:24:47.000000000 -0500
+++ libc24-ppc64-20060830/soft-fp/op-common.h 2006-09-06 10:02:49.000000000 -0500
@@ -99,10 +99,10 @@
else \
{ \
X##_e = _FP_EXPMAX_##fs - 1; \
- FP_SET_EXCEPTION(FP_EX_OVERFLOW); \
- FP_SET_EXCEPTION(FP_EX_INEXACT); \
_FP_FRAC_SET_##wc(X, _FP_MAXFRAC_##wc); \
} \
+ FP_SET_EXCEPTION(FP_EX_INEXACT); \
+ FP_SET_EXCEPTION(FP_EX_OVERFLOW); \
} while (0)
/* Check for a semi-raw value being a signaling NaN and raise the
@@ -131,10 +131,12 @@
/* Prepare to pack an fp value in semi-raw mode: the mantissa is
rounded and shifted right, with the rounding possibly increasing
- the exponent (including changing a finite value to infinity). */
+ the exponent (including changing a finite value to infinity).
+ Be sure not to round NaNs. */
#define _FP_PACK_SEMIRAW(fs, wc, X) \
do { \
- _FP_ROUND(wc, X); \
+ if(X##_e != _FP_EXPMAX_##fs) \
+ _FP_ROUND(wc, X); \
if (_FP_FRAC_HIGH_##fs(X) \
& (_FP_OVERFLOW_##fs >> 1)) \
{ \