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| author | Jakub Jelinek <jakub@redhat.com> | 2012-02-16 16:34:28 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2012-02-16 16:34:28 +0100 |
| commit | 3db93c89bcf498337b179379987d42e7aef1cd0b (patch) | |
| tree | 3b3d3f1e75c66f654e5766a8981e1f3f9e0f9992 /gcc | |
| parent | e20f6b4bde8a93aefb4bb2a9b3946a24edeea5ef (diff) | |
| download | gcc-3db93c89bcf498337b179379987d42e7aef1cd0b.zip gcc-3db93c89bcf498337b179379987d42e7aef1cd0b.tar.gz gcc-3db93c89bcf498337b179379987d42e7aef1cd0b.tar.bz2 | |
re PR rtl-optimization/52208 (Useless store)
PR rtl-optimization/52208
* ira-costs.c (scan_one_insn): Don't decrease mem_cost
for MEMs with REG_EQUIV, if the MEM isn't general_operand.
From-SVN: r184310
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/ira-costs.c | 13 |
2 files changed, 14 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e8b5efa..4ba6cbf 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,9 @@ 2012-02-16 Jakub Jelinek <jakub@redhat.com> + PR rtl-optimization/52208 + * ira-costs.c (scan_one_insn): Don't decrease mem_cost + for MEMs with REG_EQUIV, if the MEM isn't general_operand. + PR tree-optimization/52255 * tree-vect-loop-manip.c (slpeel_tree_peel_loop_to_edge): If loop->header has virtual PHI, but exit_e->dest doesn't, add diff --git a/gcc/ira-costs.c b/gcc/ira-costs.c index 8e1e846..34e6ef9 100644 --- a/gcc/ira-costs.c +++ b/gcc/ira-costs.c @@ -1,5 +1,5 @@ /* IRA hard register and memory cost calculation for allocnos or pseudos. - Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 + Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc. Contributed by Vladimir Makarov <vmakarov@redhat.com>. @@ -1306,14 +1306,21 @@ scan_one_insn (rtx insn) Similarly if we're loading other constants from memory (constant pool, TOC references, small data areas, etc) and this is the only - assignment to the destination pseudo. */ + assignment to the destination pseudo. + + Don't do this if SET_SRC (set) isn't a general operand, if it is + a memory requiring special instructions to load it, decreasing + mem_cost might result in it being loaded using the specialized + instruction into a register, then stored into stack and loaded + again from the stack. See PR52208. */ if (set != 0 && REG_P (SET_DEST (set)) && MEM_P (SET_SRC (set)) && (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != NULL_RTX && ((MEM_P (XEXP (note, 0))) || (CONSTANT_P (XEXP (note, 0)) && targetm.legitimate_constant_p (GET_MODE (SET_DEST (set)), XEXP (note, 0)) - && REG_N_SETS (REGNO (SET_DEST (set))) == 1))) + && REG_N_SETS (REGNO (SET_DEST (set))) == 1)) + && general_operand (SET_SRC (set), GET_MODE (SET_SRC (set)))) { enum reg_class cl = GENERAL_REGS; rtx reg = SET_DEST (set); |