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| author | Richard Henderson <rth@redhat.com> | 2007-04-24 08:28:21 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2007-04-24 08:28:21 -0700 |
| commit | 5fb54b91980565f03b96cadfc55dff8ddf5236ca (patch) | |
| tree | 02de3c14605545c31467f9847eec2443b8c6117d /gcc/libgcc2.c | |
| parent | 688518053c61ccb6d52aa647d6ba6b04fdc1b04c (diff) | |
| download | gcc-5fb54b91980565f03b96cadfc55dff8ddf5236ca.zip gcc-5fb54b91980565f03b96cadfc55dff8ddf5236ca.tar.gz gcc-5fb54b91980565f03b96cadfc55dff8ddf5236ca.tar.bz2 | |
libgcc2.h (AVOID_FP_TYPE_CONVERSION): Rename from IS_IBM_EXTENDED.
* libgcc2.h (AVOID_FP_TYPE_CONVERSION): Rename from
IS_IBM_EXTENDED. Also define in terms of WIDEST_HARDWARE_FP_SIZE.
* libgcc2.c (__floatdisf): Avoid double-word arithmetic when
looking for non-zero bits shifted out. Avoid a recursive call
when constructing the scalar.
(__floatundisf): Likewise.
From-SVN: r124106
Diffstat (limited to 'gcc/libgcc2.c')
| -rw-r--r-- | gcc/libgcc2.c | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/gcc/libgcc2.c b/gcc/libgcc2.c index 8c0c9d1..a026fff 100644 --- a/gcc/libgcc2.c +++ b/gcc/libgcc2.c @@ -1420,11 +1420,7 @@ __floatunditf (UDWtype u) #define F_MODE_OK(SIZE) \ (SIZE < DI_SIZE \ && SIZE > (DI_SIZE - SIZE + FSSIZE) \ - /* Don't use IBM Extended Double TFmode for TI->SF calculations. \ - The conversion from long double to float suffers from double \ - rounding, because we convert via double. In any case, the \ - fallback code is faster. */ \ - && !IS_IBM_EXTENDED (SIZE)) + && !AVOID_FP_TYPE_CONVERSION(SIZE)) #if defined(L_floatdisf) #define FUNC __floatdisf #define FSTYPE SFtype @@ -1515,13 +1511,21 @@ FUNC (DWtype u) hi = u >> shift; /* If we lost any nonzero bits, set the lsb to ensure correct rounding. */ - if (u & (((DWtype)1 << shift) - 1)) + if ((UWtype)u << (W_TYPE_SIZE - shift)) hi |= 1; /* Convert the one word of data, and rescale. */ - FSTYPE f = hi; - f *= (UDWtype)1 << shift; - return f; + FSTYPE f = hi, e; + if (shift == W_TYPE_SIZE) + e = Wtype_MAXp1_F; + /* The following two cases could be merged if we knew that the target + supported a native unsigned->float conversion. More often, we only + have a signed conversion, and have to add extra fixup code. */ + else if (shift == W_TYPE_SIZE - 1) + e = Wtype_MAXp1_F / 2; + else + e = (Wtype)1 << shift; + return f * e; #endif } #endif @@ -1532,11 +1536,7 @@ FUNC (DWtype u) #define F_MODE_OK(SIZE) \ (SIZE < DI_SIZE \ && SIZE > (DI_SIZE - SIZE + FSSIZE) \ - /* Don't use IBM Extended Double TFmode for TI->SF calculations. \ - The conversion from long double to float suffers from double \ - rounding, because we convert via double. In any case, the \ - fallback code is faster. */ \ - && !IS_IBM_EXTENDED (SIZE)) + && !AVOID_FP_TYPE_CONVERSION(SIZE)) #if defined(L_floatundisf) #define FUNC __floatundisf #define FSTYPE SFtype @@ -1620,13 +1620,21 @@ FUNC (UDWtype u) hi = u >> shift; /* If we lost any nonzero bits, set the lsb to ensure correct rounding. */ - if (u & (((UDWtype)1 << shift) - 1)) + if ((UWtype)u << (W_TYPE_SIZE - shift)) hi |= 1; /* Convert the one word of data, and rescale. */ - FSTYPE f = hi; - f *= (UDWtype)1 << shift; - return f; + FSTYPE f = hi, e; + if (shift == W_TYPE_SIZE) + e = Wtype_MAXp1_F; + /* The following two cases could be merged if we knew that the target + supported a native unsigned->float conversion. More often, we only + have a signed conversion, and have to add extra fixup code. */ + else if (shift == W_TYPE_SIZE - 1) + e = Wtype_MAXp1_F / 2; + else + e = (Wtype)1 << shift; + return f * e; #endif } #endif |