===================================================================
@@ -3796,10 +3796,8 @@ compute_ld_motion_mems (void)
{
rtx src = SET_SRC (PATTERN (insn));
rtx dest = SET_DEST (PATTERN (insn));
- rtx note = find_reg_equal_equiv_note (insn);
- rtx src_eq;
- /* Check for a simple LOAD... */
+ /* Check for a simple load. */
if (MEM_P (src) && simple_mem (src))
{
ptr = ldst_entry (src);
@@ -3814,12 +3812,11 @@ compute_ld_motion_mems (void)
invalidate_any_buried_refs (src);
}
- if (note != 0 && REG_NOTE_KIND (note) == REG_EQUAL)
- src_eq = XEXP (note, 0);
- else
- src_eq = NULL_RTX;
-
- if (src_eq != NULL_RTX
+ /* Check for a simple load through a REG_EQUAL note. */
+ rtx note = find_reg_equal_equiv_note (insn), src_eq;
+ if (note
+ && REG_NOTE_KIND (note) == REG_EQUAL
+ && (src_eq = XEXP (note, 0))
&& !(MEM_P (src_eq) && simple_mem (src_eq)))
invalidate_any_buried_refs (src_eq);
@@ -3843,7 +3840,17 @@ compute_ld_motion_mems (void)
}
}
else
- invalidate_any_buried_refs (PATTERN (insn));
+ {
+ /* Invalidate all MEMs in the pattern and... */
+ invalidate_any_buried_refs (PATTERN (insn));
+
+ /* ...in REG_EQUAL notes for PARALLELs with single SET. */
+ rtx note = find_reg_equal_equiv_note (insn), src_eq;
+ if (note
+ && REG_NOTE_KIND (note) == REG_EQUAL
+ && (src_eq = XEXP (note, 0)))
+ invalidate_any_buried_refs (src_eq);
+ }
}
}
}
It's a regression present on all active branches caused by the RTL enhanced load motion optimization (-fgcse-lm), which performs PRE on "simple" MEMs and discards all other memory references. The problem is that it fails to discard a particular memory reference present in a REG_EQUAL note: (insn 7 6 8 3 (parallel [ (set (reg:DI 88 [ _4 ]) (rotatert:DI (reg:DI 117 [ v32u64_1+24 ]) (const_int 19 [0x13]))) (clobber (reg:CC 17 flags)) ]) pr70007.c:10 607 {*rotrdi3_1} (expr_list:REG_DEAD (reg:DI 117 [ v32u64_1+24 ]) (expr_list:REG_UNUSED (reg:CC 17 flags) (expr_list:REG_EQUAL (rotatert:DI (mem/j/c:DI (plus:DI (reg/f:DI 16 argp) (const_int 88 [0x58])) [1 v32u64_1+24 S8 A64]) (const_int 19 [0x13])) (nil))))) because it only considers REG_EQUAL notes attached to SET patterns. Here it's a PARALLEL with a single SET and that's allowed by set_for_reg_notes. Tested on x86_64-suse-linux, applied on all active branches. 2016-03-01 Eric Botcazou <ebotcazou@adacore.com> PR rtl-optimization/70007 * gcse.c (compute_ld_motion_mems): Tidy up and also invalidate memory references present in REG_EQUAL notes attached to non-SET patterns. 2016-03-01 Eric Botcazou <ebotcazou@adacore.com> * gcc.target/i386/pr70007.c: New test.