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--- gcc-3.4.0/gcc/config/arm/arm.md.arm-ldm-peephole 2004-01-13 08:24:37.000000000 -0500
+++ gcc-3.4.0/gcc/config/arm/arm.md 2004-04-24 18:18:04.000000000 -0400
@@ -8810,13 +8810,16 @@
(set_attr "length" "4,8,8")]
)
+; Try to convert LDR+LDR+arith into [add+]LDM+arith
+; On XScale, LDM is always slower than two LDRs, so only do this if
+; optimising for size.
(define_insn "*arith_adjacentmem"
[(set (match_operand:SI 0 "s_register_operand" "=r")
(match_operator:SI 1 "shiftable_operator"
[(match_operand:SI 2 "memory_operand" "m")
(match_operand:SI 3 "memory_operand" "m")]))
(clobber (match_scratch:SI 4 "=r"))]
- "TARGET_ARM && adjacent_mem_locations (operands[2], operands[3])"
+ "TARGET_ARM && (!arm_tune_xscale || optimize_size) && adjacent_mem_locations (operands[2], operands[3])"
"*
{
rtx ldm[3];
@@ -8851,6 +8854,8 @@
}
if (val1 && val2)
{
+ /* This would be a loss on a Harvard core, but adjacent_mem_locations()
+ will prevent it from happening. */
rtx ops[3];
ldm[0] = ops[0] = operands[4];
ops[1] = XEXP (XEXP (operands[2], 0), 0);
--- gcc-3.4.0/gcc/genpeep.c.arm-ldm-peephole 2003-07-05 01:27:22.000000000 -0400
+++ gcc-3.4.0/gcc/genpeep.c 2004-04-24 18:18:04.000000000 -0400
@@ -381,6 +381,7 @@
printf ("#include \"recog.h\"\n");
printf ("#include \"except.h\"\n\n");
printf ("#include \"function.h\"\n\n");
+ printf ("#include \"flags.h\"\n\n");
printf ("#ifdef HAVE_peephole\n");
printf ("extern rtx peep_operand[];\n\n");
--- gcc/gcc/config/arm/arm.c.orig 2005-06-02 22:40:40.000000000 +0100
+++ gcc/gcc/config/arm/arm.c 2005-06-02 22:45:45.000000000 +0100
@@ -4610,9 +4610,12 @@
if (arm_eliminable_register (reg0))
return 0;
+ /* For Harvard cores, only accept pairs where one offset is zero.
+ See comment in load_multiple_sequence. */
val_diff = val1 - val0;
return ((REGNO (reg0) == REGNO (reg1))
- && (val_diff == 4 || val_diff == -4));
+ && (val_diff == 4 || val_diff == -4))
+ && (!arm_ld_sched || val0 == 0 || val1 == 0);
}
return 0;
@@ -4857,6 +4860,11 @@
*load_offset = unsorted_offsets[order[0]];
}
+ /* For XScale a two-word LDM is a performance loss, so only do this if
+ size is more important. See comments in arm_gen_load_multiple. */
+ if (nops == 2 && arm_tune_xscale && !optimize_size)
+ return 0;
+
if (unsorted_offsets[order[0]] == 0)
return 1; /* ldmia */
@@ -5083,6 +5091,11 @@
*load_offset = unsorted_offsets[order[0]];
}
+ /* For XScale a two-word LDM is a performance loss, so only do this if
+ size is more important. See comments in arm_gen_load_multiple. */
+ if (nops == 2 && arm_tune_xscale && !optimize_size)
+ return 0;
+
if (unsorted_offsets[order[0]] == 0)
return 1; /* stmia */
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