diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-37.c | 60 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-38.c | 12 | ||||
| -rw-r--r-- | gcc/tree-ssa-dse.c | 10 |
5 files changed, 90 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 08f91ed..d8f6004 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-07-19 Jeff Law <law@redhat.com> + + * tree-ssa-dse.c (initialize_ao_ref_for_dse): Handle + strncpy. Drop some trivial dead code. + (maybe_trim_memstar_call): Handle strncpy. + 2019-07-19 Richard Biener <rguenther@suse.de> PR tree-optimization/91211 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 98fb40d..ce8e3c7 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-07-19 Jeff Law <law@redhat.com> + + * gcc.dg/tree-ssa/ssa-dse-37.c: New test. + * gcc.dg/tree-ssa/ssa-dse-38.c: New test. + 2019-07-19 Richard Biener <rguenther@suse.de> PR tree-optimization/91211 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-37.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-37.c new file mode 100644 index 0000000..56251fc --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-37.c @@ -0,0 +1,60 @@ +/* { dg-options "-O2 -fdump-tree-dse-details -fno-tree-fre" } */ + + +#ifndef SCOPE +#define SCOPE +#endif + +extern void frob (char *); + +void g (char *s) +{ + SCOPE char a[8]; + __builtin_strncpy (a, s, sizeof a); + __builtin_memset (a, 0, sizeof a); + frob (a); +} + +void h (char *s) +{ + SCOPE char a[8]; + __builtin_memset (a, 0, sizeof a); + __builtin_strncpy (a, s, sizeof a); + frob (a); +} + +void i (char *s) +{ + SCOPE char a[8]; + __builtin_strncpy (a, s, sizeof a); + __builtin_memset (a, 0, sizeof a - 5); + frob (a); +} + +void j (char *s) +{ + SCOPE char a[8]; + __builtin_memset (a, 0, sizeof a); + __builtin_strncpy (a, s, sizeof a - 5); + frob (a); +} + +void l (char *s) +{ + SCOPE char a[8]; + __builtin_strncpy (a, s, sizeof a); + __builtin_memset (a + 2, 0, sizeof a - 2); + frob (a); +} + +void m (char *s) +{ + SCOPE char a[8]; + __builtin_memset (a, 0, sizeof a); + __builtin_strncpy (a + 2, s, sizeof a - 2); + frob (a); +} + +/* { dg-final { scan-tree-dump-times "Deleted dead call" 2 "dse1" } } */ +/* { dg-final { scan-tree-dump-times "Trimming statement " 4 "dse1" } } */ + diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-38.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-38.c new file mode 100644 index 0000000..7ae33bf --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-38.c @@ -0,0 +1,12 @@ +/* { dg-options "-O2 -fdump-tree-dse-details -fno-tree-fre" } */ + + +/* This changes the scope of the destination object and exposes + missed optimizations in DSE. */ +#define SCOPE extern +#include "ssa-dse-37.c" + +/* { dg-final { scan-tree-dump-times "Deleted dead call" 2 "dse1" { xfail *-*-* } } } */ +/* { dg-final { scan-tree-dump-times "Trimming statement " 4 "dse1" { xfail *-*-* } } } */ + + diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c index 9bdcf9a..5b7c4fc 100644 --- a/gcc/tree-ssa-dse.c +++ b/gcc/tree-ssa-dse.c @@ -113,10 +113,10 @@ initialize_ao_ref_for_dse (gimple *stmt, ao_ref *write) case BUILT_IN_MEMCPY_CHK: case BUILT_IN_MEMMOVE_CHK: case BUILT_IN_MEMSET_CHK: + case BUILT_IN_STRNCPY: + case BUILT_IN_STRNCPY_CHK: { - tree size = NULL_TREE; - if (gimple_call_num_args (stmt) == 3) - size = gimple_call_arg (stmt, 2); + tree size = gimple_call_arg (stmt, 2); tree ptr = gimple_call_arg (stmt, 0); ao_ref_init_from_ptr_and_size (write, ptr, size); return true; @@ -469,8 +469,10 @@ maybe_trim_memstar_call (ao_ref *ref, sbitmap live, gimple *stmt) { case BUILT_IN_MEMCPY: case BUILT_IN_MEMMOVE: + case BUILT_IN_STRNCPY: case BUILT_IN_MEMCPY_CHK: case BUILT_IN_MEMMOVE_CHK: + case BUILT_IN_STRNCPY_CHK: { int head_trim, tail_trim; compute_trims (ref, live, &head_trim, &tail_trim, stmt); @@ -966,9 +968,11 @@ dse_dom_walker::dse_optimize_stmt (gimple_stmt_iterator *gsi) { case BUILT_IN_MEMCPY: case BUILT_IN_MEMMOVE: + case BUILT_IN_STRNCPY: case BUILT_IN_MEMSET: case BUILT_IN_MEMCPY_CHK: case BUILT_IN_MEMMOVE_CHK: + case BUILT_IN_STRNCPY_CHK: case BUILT_IN_MEMSET_CHK: { /* Occasionally calls with an explicit length of zero |