From 710ee3ed76eeafcb4fe72a51448b7e396c436e14 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 7 Feb 2003 14:57:41 -0800 Subject: [PATCH] gcse.c (local_cprop_find_used_regs): New. * gcse.c (local_cprop_find_used_regs): New. (local_cprop_pass): Use it. From-SVN: r62555 --- gcc/ChangeLog | 6 ++++++ gcc/gcse.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 56 insertions(+), 2 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9f895084ba3..8898bea2942 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2003-02-07 Richard Henderson + + PR 9226 + * gcse.c (local_cprop_find_used_regs): New. + (local_cprop_pass): Use it. + 2003-02-07 Fred Fish * mips-tfile.c (parse_def): Parenthesize assignments to fix diff --git a/gcc/gcse.c b/gcc/gcse.c index 3adaf5ca0ac..2cc7f0b1c67 100644 --- a/gcc/gcse.c +++ b/gcc/gcse.c @@ -706,6 +706,7 @@ static void free_insn_expr_list_list PARAMS ((rtx *)); static void clear_modify_mem_tables PARAMS ((void)); static void free_modify_mem_tables PARAMS ((void)); static rtx gcse_emit_move_after PARAMS ((rtx, rtx, rtx)); +static void local_cprop_find_used_regs PARAMS ((rtx *, void *)); static bool do_local_cprop PARAMS ((rtx, rtx, int, rtx*)); static bool adjust_libcall_notes PARAMS ((rtx, rtx, rtx, rtx*)); static void local_cprop_pass PARAMS ((int)); @@ -4258,6 +4259,53 @@ cprop_insn (insn, alter_jumps) return changed; } +/* Like find_used_regs, but avoid recording uses that appear in + input-output contexts such as zero_extract or pre_dec. This + restricts the cases we consider to those for which local cprop + can legitimately make replacements. */ + +static void +local_cprop_find_used_regs (xptr, data) + rtx *xptr; + void *data; +{ + rtx x = *xptr; + + if (x == 0) + return; + + switch (GET_CODE (x)) + { + case ZERO_EXTRACT: + case SIGN_EXTRACT: + case STRICT_LOW_PART: + return; + + case PRE_DEC: + case PRE_INC: + case POST_DEC: + case POST_INC: + case PRE_MODIFY: + case POST_MODIFY: + /* Can only legitimately appear this early in the context of + stack pushes for function arguments, but handle all of the + codes nonetheless. */ + return; + + case SUBREG: + /* Setting a subreg of a register larger than word_mode leaves + the non-written words unchanged. */ + if (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) > BITS_PER_WORD) + return; + break; + + default: + break; + } + + find_used_regs (xptr, data); +} + /* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall; their REG_EQUAL notes need updating. */ @@ -4413,9 +4461,9 @@ local_cprop_pass (alter_jumps) do { reg_use_count = 0; - note_uses (&PATTERN (insn), find_used_regs, NULL); + note_uses (&PATTERN (insn), local_cprop_find_used_regs, NULL); if (note) - find_used_regs (&XEXP (note, 0), NULL); + local_cprop_find_used_regs (&XEXP (note, 0), NULL); for (reg_used = ®_use_table[0]; reg_use_count > 0; reg_used++, reg_use_count--) -- 2.30.2