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| author | J"orn Rennecke <amylaar@cygnus.co.uk> | 1998-12-01 10:00:11 +0000 |
|---|---|---|
| committer | Joern Rennecke <amylaar@gcc.gnu.org> | 1998-12-01 10:00:11 +0000 |
| commit | 2b49ee39817f8849f931611cdc13a8d18cd209c7 (patch) | |
| tree | b9995987f19d6ca65c15b71f6f69120fde1b5af5 /gcc/local-alloc.c | |
| parent | bbe348cd18f81dd9469c81ba6f498e01ca9c5a37 (diff) | |
| download | gcc-2b49ee39817f8849f931611cdc13a8d18cd209c7.tar.gz | |
local-alloc.c (function_invariant_p): New function.
* local-alloc.c (function_invariant_p): New function.
(update_equiv_regs): Use function_invariant_p instead of CONSTANT_P
to decide if an equivalence should be recorded.
* reload1.c (num_eliminable_invariants): New static variable.
(reload): Set it. Use function_invariant_p instead of CONSTANT_P
to decide if an equivalence should be recorded.
Unshare PLUS.
(calculate_needs_all_insns): Skip insns that only set an equivalence.
Take num_eliminable_invariants into account when deciding
if register elimination should be done.
(reload_as_needed): Take num_eliminable_invariants into account
when deciding if register elimination should be done.
(eliminate_regs): Handle non-constant reg_equiv_constant.
* rtl.h (function_invariant_p): Declare.
From-SVN: r24026
Diffstat (limited to 'gcc/local-alloc.c')
| -rw-r--r-- | gcc/local-alloc.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/gcc/local-alloc.c b/gcc/local-alloc.c index e8110acae0e..f112713b284 100644 --- a/gcc/local-alloc.c +++ b/gcc/local-alloc.c @@ -630,6 +630,22 @@ memref_used_between_p (memref, start, end) return 0; } +/* Return nonzero if the rtx X is invariant over the current function. */ +int +function_invariant_p (x) + rtx x; +{ + if (CONSTANT_P (x)) + return 1; + if (x == frame_pointer_rtx || x == arg_pointer_rtx) + return 1; + if (GET_CODE (x) == PLUS + && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx) + && CONSTANT_P (XEXP (x, 1))) + return 1; + return 0; +} + /* Find registers that are equivalent to a single value throughout the compilation (either because they can be referenced in memory or are set once from a single constant). Lower their priority for a register. @@ -798,7 +814,7 @@ update_equiv_regs () if (REG_N_SETS (regno) != 1 && (! note - || ! CONSTANT_P (XEXP (note, 0)) + || ! function_invariant_p (XEXP (note, 0)) || (reg_equiv_replacement[regno] && ! rtx_equal_p (XEXP (note, 0), reg_equiv_replacement[regno])))) @@ -812,7 +828,7 @@ update_equiv_regs () /* If this register is known to be equal to a constant, record that it is always equivalent to the constant. */ - if (note && CONSTANT_P (XEXP (note, 0))) + if (note && function_invariant_p (XEXP (note, 0))) PUT_MODE (note, (enum machine_mode) REG_EQUIV); /* If this insn introduces a "constant" register, decrease the priority |