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qemu/0074-tcg-optimize-further-optimize-brcond-movcond-setcond.patch
Cole Robinson 5544c1b492 Pull patches queued for qemu 1.2.1
2012-10-28 14:05:07 -04:00

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From 8d5f3ca9ccace2374fd73d46fad56decc02e0a44 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Tue, 18 Sep 2012 19:37:00 +0200
Subject: [PATCH] tcg/optimize: further optimize brcond/movcond/setcond
When both argument of brcond/movcond/setcond are the same or when one
of the two values is a constant equal to zero, it's possible to do
further optimizations.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
tcg/optimize.c | 127 ++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 76 insertions(+), 51 deletions(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index ceea644..abe016a 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -292,58 +292,88 @@ static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y)
return res;
}
+/* Return 2 if the condition can't be simplified, and the result
+ of the condition (0 or 1) if it can */
static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x,
TCGArg y, TCGCond c)
{
- switch (op_bits(op)) {
- case 32:
+ if (temps[x].state == TCG_TEMP_CONST && temps[y].state == TCG_TEMP_CONST) {
+ switch (op_bits(op)) {
+ case 32:
+ switch (c) {
+ case TCG_COND_EQ:
+ return (uint32_t)temps[x].val == (uint32_t)temps[y].val;
+ case TCG_COND_NE:
+ return (uint32_t)temps[x].val != (uint32_t)temps[y].val;
+ case TCG_COND_LT:
+ return (int32_t)temps[x].val < (int32_t)temps[y].val;
+ case TCG_COND_GE:
+ return (int32_t)temps[x].val >= (int32_t)temps[y].val;
+ case TCG_COND_LE:
+ return (int32_t)temps[x].val <= (int32_t)temps[y].val;
+ case TCG_COND_GT:
+ return (int32_t)temps[x].val > (int32_t)temps[y].val;
+ case TCG_COND_LTU:
+ return (uint32_t)temps[x].val < (uint32_t)temps[y].val;
+ case TCG_COND_GEU:
+ return (uint32_t)temps[x].val >= (uint32_t)temps[y].val;
+ case TCG_COND_LEU:
+ return (uint32_t)temps[x].val <= (uint32_t)temps[y].val;
+ case TCG_COND_GTU:
+ return (uint32_t)temps[x].val > (uint32_t)temps[y].val;
+ }
+ break;
+ case 64:
+ switch (c) {
+ case TCG_COND_EQ:
+ return (uint64_t)temps[x].val == (uint64_t)temps[y].val;
+ case TCG_COND_NE:
+ return (uint64_t)temps[x].val != (uint64_t)temps[y].val;
+ case TCG_COND_LT:
+ return (int64_t)temps[x].val < (int64_t)temps[y].val;
+ case TCG_COND_GE:
+ return (int64_t)temps[x].val >= (int64_t)temps[y].val;
+ case TCG_COND_LE:
+ return (int64_t)temps[x].val <= (int64_t)temps[y].val;
+ case TCG_COND_GT:
+ return (int64_t)temps[x].val > (int64_t)temps[y].val;
+ case TCG_COND_LTU:
+ return (uint64_t)temps[x].val < (uint64_t)temps[y].val;
+ case TCG_COND_GEU:
+ return (uint64_t)temps[x].val >= (uint64_t)temps[y].val;
+ case TCG_COND_LEU:
+ return (uint64_t)temps[x].val <= (uint64_t)temps[y].val;
+ case TCG_COND_GTU:
+ return (uint64_t)temps[x].val > (uint64_t)temps[y].val;
+ }
+ break;
+ }
+ } else if (temps_are_copies(x, y)) {
switch (c) {
- case TCG_COND_EQ:
- return (uint32_t)x == (uint32_t)y;
- case TCG_COND_NE:
- return (uint32_t)x != (uint32_t)y;
- case TCG_COND_LT:
- return (int32_t)x < (int32_t)y;
- case TCG_COND_GE:
- return (int32_t)x >= (int32_t)y;
- case TCG_COND_LE:
- return (int32_t)x <= (int32_t)y;
case TCG_COND_GT:
- return (int32_t)x > (int32_t)y;
case TCG_COND_LTU:
- return (uint32_t)x < (uint32_t)y;
- case TCG_COND_GEU:
- return (uint32_t)x >= (uint32_t)y;
- case TCG_COND_LEU:
- return (uint32_t)x <= (uint32_t)y;
+ case TCG_COND_LT:
case TCG_COND_GTU:
- return (uint32_t)x > (uint32_t)y;
- }
- break;
- case 64:
- switch (c) {
- case TCG_COND_EQ:
- return (uint64_t)x == (uint64_t)y;
case TCG_COND_NE:
- return (uint64_t)x != (uint64_t)y;
- case TCG_COND_LT:
- return (int64_t)x < (int64_t)y;
+ return 0;
case TCG_COND_GE:
- return (int64_t)x >= (int64_t)y;
+ case TCG_COND_GEU:
case TCG_COND_LE:
- return (int64_t)x <= (int64_t)y;
- case TCG_COND_GT:
- return (int64_t)x > (int64_t)y;
+ case TCG_COND_LEU:
+ case TCG_COND_EQ:
+ return 1;
+ }
+ } else if (temps[y].state == TCG_TEMP_CONST && temps[y].val == 0) {
+ switch (c) {
case TCG_COND_LTU:
- return (uint64_t)x < (uint64_t)y;
+ return 0;
case TCG_COND_GEU:
- return (uint64_t)x >= (uint64_t)y;
- case TCG_COND_LEU:
- return (uint64_t)x <= (uint64_t)y;
- case TCG_COND_GTU:
- return (uint64_t)x > (uint64_t)y;
+ return 1;
+ default:
+ return 2;
}
- break;
+ } else {
+ return 2;
}
fprintf(stderr,
@@ -636,11 +666,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
args += 3;
break;
CASE_OP_32_64(setcond):
- if (temps[args[1]].state == TCG_TEMP_CONST
- && temps[args[2]].state == TCG_TEMP_CONST) {
+ tmp = do_constant_folding_cond(op, args[1], args[2], args[3]);
+ if (tmp != 2) {
gen_opc_buf[op_index] = op_to_movi(op);
- tmp = do_constant_folding_cond(op, temps[args[1]].val,
- temps[args[2]].val, args[3]);
tcg_opt_gen_movi(gen_args, args[0], tmp);
gen_args += 2;
} else {
@@ -654,10 +682,9 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
args += 4;
break;
CASE_OP_32_64(brcond):
- if (temps[args[0]].state == TCG_TEMP_CONST
- && temps[args[1]].state == TCG_TEMP_CONST) {
- if (do_constant_folding_cond(op, temps[args[0]].val,
- temps[args[1]].val, args[2])) {
+ tmp = do_constant_folding_cond(op, args[0], args[1], args[2]);
+ if (tmp != 2) {
+ if (tmp) {
memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
gen_opc_buf[op_index] = INDEX_op_br;
gen_args[0] = args[3];
@@ -677,10 +704,8 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
args += 4;
break;
CASE_OP_32_64(movcond):
- if (temps[args[1]].state == TCG_TEMP_CONST
- && temps[args[2]].state == TCG_TEMP_CONST) {
- tmp = do_constant_folding_cond(op, temps[args[1]].val,
- temps[args[2]].val, args[5]);
+ tmp = do_constant_folding_cond(op, args[1], args[2], args[5]);
+ if (tmp != 2) {
if (temps_are_copies(args[0], args[4-tmp])) {
gen_opc_buf[op_index] = INDEX_op_nop;
} else if (temps[args[4-tmp]].state == TCG_TEMP_CONST) {
--
1.7.12.1
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