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| author | Richard Biener <rguenther@suse.de> | 2016-04-04 09:30:16 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-04-04 09:30:16 +0000 |
| commit | 43b9f499103ccebb9ce00e7c62e11da54334e63a (patch) | |
| tree | 6684fdba1e474d2726d62599732082794132c876 | |
| parent | ed2a53e7ca7aafa5fea5316c7fdebdc77fb8f327 (diff) | |
| download | gcc-43b9f499103ccebb9ce00e7c62e11da54334e63a.zip gcc-43b9f499103ccebb9ce00e7c62e11da54334e63a.tar.gz gcc-43b9f499103ccebb9ce00e7c62e11da54334e63a.tar.bz2 | |
re PR rtl-optimization/70484 (Wrong optimization with aliasing and access via char)
2016-04-04 Richard Biener <rguenther@suse.de>
PR rtl-optimization/70484
* rtl.h (canon_output_dependence): Declare.
* alias.c (canon_output_dependence): New function.
* dse.c (record_store): Use canon_output_dependence rather
than canon_true_dependence.
* gcc.dg/torture/pr70484.c: New testcase.
From-SVN: r234709
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/alias.c | 14 | ||||
| -rw-r--r-- | gcc/dse.c | 7 | ||||
| -rw-r--r-- | gcc/rtl.h | 2 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr70484.c | 19 |
6 files changed, 51 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6151525..83f3454 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2016-04-04 Richard Biener <rguenther@suse.de> + + PR rtl-optimization/70484 + * rtl.h (canon_output_dependence): Declare. + * alias.c (canon_output_dependence): New function. + * dse.c (record_store): Use canon_output_dependence rather + than canon_true_dependence. + 2016-03-30 Jan Hubicka <hubicka@ucw.cz> PR ipa/68881 diff --git a/gcc/alias.c b/gcc/alias.c index 753e1af..a0e25dc 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -3057,6 +3057,20 @@ output_dependence (const_rtx mem, const_rtx x) /*mem_canonicalized=*/false, /*x_canonicalized*/false, /*writep=*/true); } + +/* Likewise, but we already have a canonicalized MEM, and X_ADDR for X. + Also, consider X in X_MODE (which might be from an enclosing + STRICT_LOW_PART / ZERO_EXTRACT). + If MEM_CANONICALIZED is true, MEM is canonicalized. */ + +int +canon_output_dependence (const_rtx mem, bool mem_canonicalized, + const_rtx x, machine_mode x_mode, rtx x_addr) +{ + return write_dependence_p (mem, x, x_mode, x_addr, + mem_canonicalized, /*x_canonicalized=*/true, + /*writep=*/true); +} @@ -1609,10 +1609,9 @@ record_store (rtx body, bb_info_t bb_info) the value of store_info. If it is, set the rhs to NULL to keep it from being used to remove a load. */ { - if (canon_true_dependence (s_info->mem, - GET_MODE (s_info->mem), - s_info->mem_addr, - mem, mem_addr)) + if (canon_output_dependence (s_info->mem, true, + mem, GET_MODE (mem), + mem_addr)) { s_info->rhs = NULL; s_info->const_rhs = NULL; @@ -3652,6 +3652,8 @@ extern int anti_dependence (const_rtx, const_rtx); extern int canon_anti_dependence (const_rtx, bool, const_rtx, machine_mode, rtx); extern int output_dependence (const_rtx, const_rtx); +extern int canon_output_dependence (const_rtx, bool, + const_rtx, machine_mode, rtx); extern int may_alias_p (const_rtx, const_rtx); extern void init_alias_target (void); extern void init_alias_analysis (void); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a8bd711..43bad0f 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-04-04 Richard Biener <rguenther@suse.de> + + PR rtl-optimization/70484 + * gcc.dg/torture/pr70484.c: New testcase. + 2016-04-04 Marek Polacek <polacek@redhat.com> PR c/70307 diff --git a/gcc/testsuite/gcc.dg/torture/pr70484.c b/gcc/testsuite/gcc.dg/torture/pr70484.c new file mode 100644 index 0000000..7604c65 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr70484.c @@ -0,0 +1,19 @@ +/* { dg-do run } */ + +extern void abort (void); + +int __attribute__((noinline,noclone)) +f(int *pi, long *pl) +{ + *pi = 1; + *pl = 0; + return *(char *)pi; +} + +int main() +{ + union { long l; int i; } a; + if (f (&a.i, &a.l) != 0) + abort (); + return 0; +} |