| Message ID | 1409803667.3163.46.camel@gnopaine |
|---|---|
| State | New |
| Headers | show |
On Thu, Sep 4, 2014 at 12:07 AM, Bill Schmidt <wschmidt@linux.vnet.ibm.com> wrote: > Hi, > > The *vsx_extract_<mode>_load pattern performs a scalar load of memory > when possible, rather than a vector load followed by an extract. The > assembly for the pattern always loads the 0th memory doubleword element, > but the pattern match selects the 0th for big-endian and the 1st for > little-endian, leading to wrong results for LE. This patch changes the > pattern match to look for the 0th element regardless of endianness. > > I ran across this when working on another patch, which provides more > test coverage for this scenario and will be submitted shortly. For this > patch, I'm just correcting the now-failing vsx-extract-1.c test. > > Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no > regressions. Ok for trunk? (This should eventually be backported to > 4.8 and 4.9 as well...) > > Thanks, > Bill > > > [gcc] > > 2014-09-03 Bill Schmidt <wschmidt@linux.vnet.ibm.com> > > * config/rs6000/vsx.md (*vsx_extract_<mode>_load): Always match > selection of 0th memory doubleword, regardless of endianness. > > [gcc/testsuite] > > 2014-09-03 Bill Schmidt <wschmidt@linux.vnet.ibm.com> > > * gcc.target/powerpc/vsx-extract-1.c: Test 0th doubleword > regardless of endianness. Okay. Thanks, David
Index: gcc/config/rs6000/vsx.md =================================================================== --- gcc/config/rs6000/vsx.md (revision 214897) +++ gcc/config/rs6000/vsx.md (working copy) @@ -1835,7 +1835,7 @@ [(set (match_operand:<VS_scalar> 0 "register_operand" "=d,wv,wr") (vec_select:<VS_scalar> (match_operand:VSX_D 1 "memory_operand" "m,Z,m") - (parallel [(match_operand:QI 2 "vsx_scalar_64bit" "wD,wD,wD")])))] + (parallel [(const_int 0)])))] "VECTOR_MEM_VSX_P (<MODE>mode)" "@ lfd%U1%X1 %0,%1 Index: gcc/testsuite/gcc.target/powerpc/vsx-extract-1.c =================================================================== --- gcc/testsuite/gcc.target/powerpc/vsx-extract-1.c (revision 214897) +++ gcc/testsuite/gcc.target/powerpc/vsx-extract-1.c (working copy) @@ -7,10 +7,4 @@ #include <altivec.h> -#if __LITTLE_ENDIAN__ -#define OFFSET 1 -#else -#define OFFSET 0 -#endif - -double get_value (vector double *p) { return vec_extract (*p, OFFSET); } +double get_value (vector double *p) { return vec_extract (*p, 0); }