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authorjakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>2012-02-16 15:34:28 +0000
committerjakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>2012-02-16 15:34:28 +0000
commit72e3d3638d3d464d276b13b2fa9b86c55a08c40f (patch)
tree3b3d3f1e75c66f654e5766a8981e1f3f9e0f9992 /gcc/ira-costs.c
parent38091110b0abe5afe1594f002f58521fd02b46d3 (diff)
downloadgcc-72e3d3638d3d464d276b13b2fa9b86c55a08c40f.tar.gz
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. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@184310 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ira-costs.c')
-rw-r--r--gcc/ira-costs.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/gcc/ira-costs.c b/gcc/ira-costs.c
index 8e1e8466437..34e6ef9346b 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);