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| author | John Wehle <john@feith.com> | 2000-08-18 02:41:58 +0000 |
|---|---|---|
| committer | John Wehle <wehle@gcc.gnu.org> | 2000-08-18 02:41:58 +0000 |
| commit | 4998268292c6b27cdd51e180ac0780f1dfaa0b08 (patch) | |
| tree | af730819a32f206d6a1042985debacae42c99c19 /gcc/alias.c | |
| parent | 889e5964f263e0aa95663bebb10c176ee79d9402 (diff) | |
| download | gcc-4998268292c6b27cdd51e180ac0780f1dfaa0b08.zip gcc-4998268292c6b27cdd51e180ac0780f1dfaa0b08.tar.gz gcc-4998268292c6b27cdd51e180ac0780f1dfaa0b08.tar.bz2 | |
alias.c (true_dependence, [...]): A read involving a label_ref or the constant pool doesn't create a dependency.
* alias.c (true_dependence, write_dependence_p): A read
involving a label_ref or the constant pool doesn't create
a dependency.
* rtl.h (unchanging): Improve documentation.
From-SVN: r35771
Diffstat (limited to 'gcc/alias.c')
| -rw-r--r-- | gcc/alias.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/gcc/alias.c b/gcc/alias.c index f879da3..ae86638 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -1566,6 +1566,7 @@ true_dependence (mem, mem_mode, x, varies) int (*varies) PARAMS ((rtx)); { register rtx x_addr, mem_addr; + rtx base; if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) return 1; @@ -1583,6 +1584,12 @@ true_dependence (mem, mem_mode, x, varies) if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem)) return 0; + base = find_base_term (x); + if (base && (GET_CODE (base) == LABEL_REF + || (GET_CODE (base) == SYMBOL_REF + && CONSTANT_POOL_ADDRESS_P (base)))) + return 0; + if (mem_mode == VOIDmode) mem_mode = GET_MODE (mem); @@ -1627,6 +1634,7 @@ write_dependence_p (mem, x, writep) { rtx x_addr, mem_addr; rtx fixed_scalar; + rtx base; if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem)) return 1; @@ -1637,8 +1645,18 @@ write_dependence_p (mem, x, writep) /* If MEM is an unchanging read, then it can't possibly conflict with the store to X, because there is at most one store to MEM, and it must have occurred somewhere before MEM. */ - if (!writep && RTX_UNCHANGING_P (mem)) - return 0; + if (! writep) + { + if (RTX_UNCHANGING_P (mem)) + return 0; + + base = find_base_term (mem); + if (base && (GET_CODE (base) == LABEL_REF + || (GET_CODE (base) == SYMBOL_REF + && CONSTANT_POOL_ADDRESS_P (base)))) + return 0; + } + x_addr = get_addr (XEXP (x, 0)); mem_addr = get_addr (XEXP (mem, 0)); |