haraldwolff/qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

target/arm: Use the int-to-float-scale softfloat routines

Browse source 
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180814002653.12828-4-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2018-08-24 13:17:30 +01:00 committed by Peter Maydell
parent 2f6c74be59
commit b9b903cf24
1 changed files with 5 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
target/arm/helper.c
View file

@ -11564,12 +11564,7 @@ float32 VFP_HELPER(fcvts, d)(float64 x, CPUARMState *env)
#define VFP_CONV_FIX_FLOAT(name, p, fsz, isz, itype) \
float##fsz HELPER(vfp_##name##to##p)(uint##isz##_t x, uint32_t shift, \
void *fpstp) \
{ \
float_status *fpst = fpstp; \
float##fsz tmp; \
tmp = itype##_to_##float##fsz(x, fpst); \
return float##fsz##_scalbn(tmp, -(int)shift, fpst); \
}
{ return itype##_to_##float##fsz##_scalbn(x, -shift, fpstp); }
/* Notice that we want only input-denormal exception flags from the
* scalbn operation: the other possible flags (overflow+inexact if
@ -11622,38 +11617,24 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64)
#undef VFP_CONV_FLOAT_FIX_ROUND
#undef VFP_CONV_FIX_A64
/* Conversion to/from f16 can overflow to infinity before/after scaling.
* Therefore we convert to f64, scale, and then convert f64 to f16; or
* vice versa for conversion to integer.
*
* For 16- and 32-bit integers, the conversion to f64 never rounds.
* For 64-bit integers, any integer that would cause rounding will also
* overflow to f16 infinity, so there is no double rounding problem.
*/
static float16 do_postscale_fp16(float64 f, int shift, float_status *fpst)
{
return float64_to_float16(float64_scalbn(f, -shift, fpst), true, fpst);
}
uint32_t HELPER(vfp_sltoh)(uint32_t x, uint32_t shift, void *fpst)
{
return do_postscale_fp16(int32_to_float64(x, fpst), shift, fpst);
return int32_to_float16_scalbn(x, -shift, fpst);
}
uint32_t HELPER(vfp_ultoh)(uint32_t x, uint32_t shift, void *fpst)
{
return do_postscale_fp16(uint32_to_float64(x, fpst), shift, fpst);
return uint32_to_float16_scalbn(x, -shift, fpst);
}
uint32_t HELPER(vfp_sqtoh)(uint64_t x, uint32_t shift, void *fpst)
{
return do_postscale_fp16(int64_to_float64(x, fpst), shift, fpst);
return int64_to_float16_scalbn(x, -shift, fpst);
}
uint32_t HELPER(vfp_uqtoh)(uint64_t x, uint32_t shift, void *fpst)
{
return do_postscale_fp16(uint64_to_float64(x, fpst), shift, fpst);
return uint64_to_float16_scalbn(x, -shift, fpst);
}
static float64 do_prescale_fp16(float16 f, int shift, float_status *fpst)