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| author | Michael Hayes <m.hayes@elec.canterbury.ac.nz> | 1998-12-03 01:32:23 +0000 |
|---|---|---|
| committer | Michael Hayes <m.hayes@gcc.gnu.org> | 1998-12-03 01:32:23 +0000 |
| commit | 39cec1ac5ac3dec3a6f22dc60587326f5f5dc4ef (patch) | |
| tree | 784e2a2f3a4aa6bf5c9f17a4f251a307531cf5b0 | |
| parent | 5cf068b168182de3a080a3ec60abfb564b9262b9 (diff) | |
| download | gcc-39cec1ac5ac3dec3a6f22dc60587326f5f5dc4ef.zip gcc-39cec1ac5ac3dec3a6f22dc60587326f5f5dc4ef.tar.gz gcc-39cec1ac5ac3dec3a6f22dc60587326f5f5dc4ef.tar.bz2 | |
alias.c (addr_side_effect_eval): New function.
* alias.c (addr_side_effect_eval): New function.
(memrefs_conflict_p): Use it.
* rtl.h (addr_side_effect_eval): Prototype it.
From-SVN: r24068
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/alias.c | 43 | ||||
| -rw-r--r-- | gcc/rtl.h | 1 |
3 files changed, 49 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2134c4e..2481c16 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +Thu Dec 3 22:30:18 1998 Michael Hayes <m.hayes@elec.canterbury.ac.nz> + + * alias.c (addr_side_effect_eval): New function. + (memrefs_conflict_p): Use it. + * rtl.h (addr_side_effect_eval): Prototype it. + + 1998-12-02 Joseph S. Myers <jsm28@cam.ac.uk> * pdp11.md (extendsfdf2): Fix mode mismatch in SET. diff --git a/gcc/alias.c b/gcc/alias.c index 719b890..909176e 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -860,6 +860,45 @@ base_alias_check (x, y, x_mode, y_mode) return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode); } +/* Return the address of the (N_REFS + 1)th memory reference to ADDR + where SIZE is the size in bytes of the memory reference. If ADDR + is not modified by the memory reference then ADDR is returned. */ + +rtx +addr_side_effect_eval (addr, size, n_refs) + rtx addr; + int size; + int n_refs; +{ + int offset = 0; + + switch (GET_CODE (addr)) + { + case PRE_INC: + offset = (n_refs + 1) * size; + break; + case PRE_DEC: + offset = -(n_refs + 1) * size; + break; + case POST_INC: + offset = n_refs * size; + break; + case POST_DEC: + offset = -n_refs * size; + break; + + default: + return addr; + } + + if (offset) + addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), GEN_INT (offset)); + else + addr = XEXP (addr, 0); + + return addr; +} + /* Return nonzero if X and Y (memory addresses) could reference the same location in memory. C is an offset accumulator. When C is nonzero, we are testing aliases between X and Y + C. @@ -889,13 +928,13 @@ memrefs_conflict_p (xsize, x, ysize, y, c) else if (GET_CODE (x) == LO_SUM) x = XEXP (x, 1); else - x = canon_rtx (x); + x = canon_rtx (addr_side_effect_eval (x, xsize, 0)); if (GET_CODE (y) == HIGH) y = XEXP (y, 0); else if (GET_CODE (y) == LO_SUM) y = XEXP (y, 1); else - y = canon_rtx (y); + y = canon_rtx (addr_side_effect_eval (y, ysize, 0)); if (rtx_equal_for_memref_p (x, y)) { @@ -1521,5 +1521,6 @@ extern void end_alias_analysis PROTO ((void)); extern void record_base_value PROTO ((int, rtx, int)); extern void record_alias_subset PROTO ((int, int)); +extern rtx addr_side_effect_eval PROTO ((rtx, int, int)); #endif /* _RTL_H */ |