diff options
| author | Jiufu Guo <guojiufu@linux.ibm.com> | 2020-03-10 13:51:57 +0800 |
|---|---|---|
| committer | Jiufu Guo <guojiufu@linux.ibm.com> | 2020-03-11 09:34:39 +0800 |
| commit | 37e0df8a9be5a8232f4ccb73cdadb02121ba523f (patch) | |
| tree | 6e5892773073ca2e3964bc81de76cdd97dc5d98c | |
| parent | 76743c8a6abbe29fe0f20fc55d5d691ff62dee6a (diff) | |
| download | gcc-37e0df8a9be5a8232f4ccb73cdadb02121ba523f.zip gcc-37e0df8a9be5a8232f4ccb73cdadb02121ba523f.tar.gz gcc-37e0df8a9be5a8232f4ccb73cdadb02121ba523f.tar.bz2 | |
rs6000: Check -+0 and NaN for smax/smin generation
PR93709 mentioned regressions on maxlocval_4.f90 and minlocval_f.f90 which
relates to max of '-inf' and 'nan'. This regression occur on P9 because
P9 new instruction 'xsmaxcdp' is generated.
And for C code `a < b ? b : a` is also generated as `xsmaxcdp` under -O2
for P9. While this instruction behavior more like C/C++ semantic (a>b?a:b).
This generates prevents 'xsmaxcdp' to be generated for those cases.
'xsmincdp' also is handled in patch.
gcc/
2020-03-10 Jiufu Guo <guojiufu@linux.ibm.com>
PR target/93709
* gcc/config/rs6000/rs6000.c (rs6000_emit_p9_fp_minmax): Check
NAN and SIGNED_ZEROR for smax/smin.
gcc/testsuite
2020-03-10 Jiufu Guo <guojiufu@linux.ibm.com>
PR target/93709
* gcc.target/powerpc/p9-minmax-3.c: New test.
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/config/rs6000/rs6000.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/powerpc/p9-minmax-3.c | 17 |
4 files changed, 33 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c525661..5b67b79 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-03-10 Jiufu Guo <guojiufu@linux.ibm.com> + + PR target/93709 + * gcc/config/rs6000/rs6000.c (rs6000_emit_p9_fp_minmax): Check + NAN and SIGNED_ZEROR for smax/smin. + 2020-03-10 Will Schmidt <will_schmidt@vnet.ibm.com> PR target/90763 diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index 848a4ef..46b7dec 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -14831,7 +14831,11 @@ rs6000_emit_p9_fp_minmax (rtx dest, rtx op, rtx true_cond, rtx false_cond) if (rtx_equal_p (op0, true_cond) && rtx_equal_p (op1, false_cond)) ; - else if (rtx_equal_p (op1, true_cond) && rtx_equal_p (op0, false_cond)) + /* Only when NaNs and signed-zeros are not in effect, smax could be + used for `op0 < op1 ? op1 : op0`, and smin could be used for + `op0 > op1 ? op1 : op0`. */ + else if (rtx_equal_p (op1, true_cond) && rtx_equal_p (op0, false_cond) + && !HONOR_NANS (compare_mode) && !HONOR_SIGNED_ZEROS (compare_mode)) max_p = !max_p; else diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index da525a3..c76d891 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-03-10 Jiufu Guo <guojiufu@linux.ibm.com> + + PR target/93709 + * gcc.target/powerpc/p9-minmax-3.c: New test. + 2020-03-10 Will Schmidt <will_schmidt@vnet.ibm.com> PR target/90763 diff --git a/gcc/testsuite/gcc.target/powerpc/p9-minmax-3.c b/gcc/testsuite/gcc.target/powerpc/p9-minmax-3.c new file mode 100644 index 0000000..141603e --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/p9-minmax-3.c @@ -0,0 +1,17 @@ +/* { dg-do compile { target { powerpc*-*-* } } } */ +/* { dg-require-effective-target powerpc_p9vector_ok } */ +/* { dg-options "-mdejagnu-cpu=power9 -O2 -mpower9-minmax" } */ +/* { dg-final { scan-assembler-not "xsmaxcdp" } } */ +/* { dg-final { scan-assembler-not "xsmincdp" } } */ + +double +dbl_max1 (double a, double b) +{ + return a < b ? b : a; +} + +double +dbl_min1 (double a, double b) +{ + return a > b ? b : a; +} |