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| author | Jim Wilson <wilson@cygnus.com> | 1997-09-03 19:28:49 +0000 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1997-09-03 12:28:49 -0700 |
| commit | fa8b60246437510ca70a89f5d9a127849f4228e5 (patch) | |
| tree | 6f784566b8cf913929bf3bb2e772812c549daac1 /gcc | |
| parent | 03e707055891d5eaaf5dc9e850123bd2dd16ba38 (diff) | |
| download | gcc-fa8b60246437510ca70a89f5d9a127849f4228e5.zip gcc-fa8b60246437510ca70a89f5d9a127849f4228e5.tar.gz gcc-fa8b60246437510ca70a89f5d9a127849f4228e5.tar.bz2 | |
Fix H.J. Lu's alpha-linux aliasing bug.
* alias.c (true_dependence): Address with AND can alias scalars.
(anti_dependence, output_dependence): Likewise.
From-SVN: r15063
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/alias.c | 12 |
2 files changed, 13 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 190eb48..e77c1c6 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,8 @@ Wed Sep 3 10:39:42 1997 Jim Wilson <wilson@cygnus.com> + * alias.c (true_dependence): Address with AND can alias scalars. + (anti_dependence, output_dependence): Likewise. + * alias.c (true_dependence): Test x for BLKmode, in addition to mem. Wed Sep 3 09:28:50 CDT 1997 Joel Sherrill (joel@OARcorp.com) diff --git a/gcc/alias.c b/gcc/alias.c index cb3a917..4c2ca48 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -751,11 +751,14 @@ memrefs_conflict_p (xsize, x, ysize, y, c) changed. A volatile and non-volatile reference can be interchanged though. - A MEM_IN_STRUCT reference at a non-QImode varying address can never + A MEM_IN_STRUCT reference at a non-QImode non-AND varying address can never conflict with a non-MEM_IN_STRUCT reference at a fixed address. We must allow QImode aliasing because the ANSI C standard allows character pointers to alias anything. We are assuming that characters are - always QImode here. */ + always QImode here. We also must allow AND addresses, because they may + generate accesses outside the object being referenced. This is used to + generate aligned addresses from unaligned addresses, for instance, the + alpha storeqi_unaligned pattern. */ /* Read dependence: X is read after read in MEM takes place. There can only be a dependence here if both reads are volatile. */ @@ -816,6 +819,7 @@ true_dependence (mem, mem_mode, x, varies) if (MEM_IN_STRUCT_P (x) == MEM_IN_STRUCT_P (mem) || mem_mode == QImode || mem_mode == BLKmode || GET_MODE (x) == QImode || GET_MODE (x) == BLKmode + || GET_CODE (x_addr) == AND || GET_CODE (mem_addr) == AND || varies (x_addr) == varies (mem_addr)) return 1; @@ -856,9 +860,11 @@ anti_dependence (mem, x) SIZE_FOR_MODE (x), XEXP (x, 0), 0) && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) && GET_MODE (mem) != QImode + && GET_CODE (XEXP (mem, 0)) != AND && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) && GET_MODE (x) != QImode + && GET_CODE (XEXP (x, 0)) != AND && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem))); } @@ -881,9 +887,11 @@ output_dependence (mem, x) SIZE_FOR_MODE (x), XEXP (x, 0), 0) && ! (MEM_IN_STRUCT_P (mem) && rtx_addr_varies_p (mem) && GET_MODE (mem) != QImode + && GET_CODE (XEXP (mem, 0)) != AND && ! MEM_IN_STRUCT_P (x) && ! rtx_addr_varies_p (x)) && ! (MEM_IN_STRUCT_P (x) && rtx_addr_varies_p (x) && GET_MODE (x) != QImode + && GET_CODE (XEXP (x, 0)) != AND && ! MEM_IN_STRUCT_P (mem) && ! rtx_addr_varies_p (mem))); } |