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| author | Andreas Krebbel <krebbel@linux.ibm.com> | 2020-06-17 17:10:05 +0200 |
|---|---|---|
| committer | Andreas Krebbel <krebbel@linux.ibm.com> | 2020-06-17 17:11:45 +0200 |
| commit | 914eadfe86a0400e0e378819001c785ecb30aab2 (patch) | |
| tree | 79fdaf5aa7f9707f45b2a0b329480319ffcb4bdb /gcc | |
| parent | 8a9e230f41eb406380ab0d9c2b73031133d54259 (diff) | |
| download | gcc-914eadfe86a0400e0e378819001c785ecb30aab2.zip gcc-914eadfe86a0400e0e378819001c785ecb30aab2.tar.gz gcc-914eadfe86a0400e0e378819001c785ecb30aab2.tar.bz2 | |
IBM Z: Prevent mach optimization on doloop patterns
s390_fix_long_loop_prediction is used in machine dependent
reorg. There we use single_set to distingiush between conditional
jumps and branch on count patterns. However, single_set returns a
non-NULL value also for PARALLELs in case one of the SETs is dead.
2020-06-17 Andreas Krebbel <krebbel@linux.ibm.com>
gcc/
* config/s390/s390.c (s390_fix_long_loop_prediction): Exit early
for PARALLELs.
gcc/testsuite/
* gcc.target/s390/20200617.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/s390/s390.c | 9 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/s390/20200617.c | 23 |
2 files changed, 30 insertions, 2 deletions
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c index 758315c..bd49a89 100644 --- a/gcc/config/s390/s390.c +++ b/gcc/config/s390/s390.c @@ -13957,8 +13957,13 @@ s390_fix_long_loop_prediction (rtx_insn *insn) int distance; /* This will exclude branch on count and branch on index patterns - since these are correctly statically predicted. */ - if (!set + since these are correctly statically predicted. + + The additional check for a PARALLEL is required here since + single_set might be != NULL for PARALLELs where the set of the + iteration variable is dead. */ + if (GET_CODE (PATTERN (insn)) == PARALLEL + || !set || SET_DEST (set) != pc_rtx || GET_CODE (SET_SRC(set)) != IF_THEN_ELSE) return false; diff --git a/gcc/testsuite/gcc.target/s390/20200617.c b/gcc/testsuite/gcc.target/s390/20200617.c new file mode 100644 index 0000000..067d2e1 --- /dev/null +++ b/gcc/testsuite/gcc.target/s390/20200617.c @@ -0,0 +1,23 @@ +/* This ICE'd before f9e1ea10e657af9fb02fafecf1a600740fd34409 because + a doloop pattern with a dead set of the iteration variable was + generated and s390_fix_long_loop_prediction then failed to + recognize it as branch on count pattern. */ + +/* { dg-do compile } */ +/* { dg-options "-O3 -march=z10" } */ + +int a, d, e, f; +long b; +long *volatile c; +void +fn1() { + for (; e; ++e) + if (d) + ; + else { + a = 0; + for (; a != 14; ++a) + *c = b && f; + d = 8; + } +} |