From ff596ca15ca105fc571e95cdf35c074cb4f011d4 Mon Sep 17 00:00:00 2001
From: Oleg Endo <olegendo@gcc.gnu.org>
Date: Tue, 4 Sep 2012 08:03:01 +0000
Subject: [PATCH] re PR target/51244 ([SH] Inefficient conditional branch and
code around T bit)
PR target/51244
* config/sh/sh.c (prepare_cbranch_operands): Pull out comparison
canonicalization code into...
* (sh_canonicalize_comparison): This new function.
* config/sh/sh-protos.h: Declare it.
* config/sh/sh.h: Use it in new macro CANONICALIZE_COMPARISON.
* config/sh/sh.md (cbranchsi4): Remove TARGET_CBRANCHDI4 check and
always invoke expand_cbranchsi4.
From-SVN: r190909
---
gcc/ChangeLog | 11 +++
gcc/config/sh/sh-protos.h | 3 +
gcc/config/sh/sh.c | 160 ++++++++++++++++++++++++++------------
gcc/config/sh/sh.h | 4 +
gcc/config/sh/sh.md | 5 +-
5 files changed, 131 insertions(+), 52 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a433bad52a99..059967a8c3b7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2012-09-04 Oleg Endo <olegendo@gcc.gnu.org>
+
+ PR target/51244
+ * config/sh/sh.c (prepare_cbranch_operands): Pull out comparison
+ canonicalization code into...
+ * (sh_canonicalize_comparison): This new function.
+ * config/sh/sh-protos.h: Declare it.
+ * config/sh/sh.h: Use it in new macro CANONICALIZE_COMPARISON.
+ * config/sh/sh.md (cbranchsi4): Remove TARGET_CBRANCHDI4 check and
+ always invoke expand_cbranchsi4.
+
2012-09-03 Andi Kleen <ak@linux.intel.com>
* tree-ssa-sccvn.c (vn_reference_fold_indirect): Initialize
diff --git a/gcc/config/sh/sh-protos.h b/gcc/config/sh/sh-protos.h
index 8cc5cc6b4888..2bb318b1bc32 100644
--- a/gcc/config/sh/sh-protos.h
+++ b/gcc/config/sh/sh-protos.h
@@ -106,6 +106,9 @@ extern bool sh_expand_t_scc (rtx *);
extern rtx sh_gen_truncate (enum machine_mode, rtx, int);
extern bool sh_vector_mode_supported_p (enum machine_mode);
extern bool sh_cfun_trap_exit_p (void);
+extern void sh_canonicalize_comparison (enum rtx_code&, rtx&, rtx&,
+ enum machine_mode mode = VOIDmode);
+
#endif /* RTX_CODE */
extern const char *output_jump_label_table (void);
diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index 3851ec6d50f3..5055d1ff929e 100644
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -21,6 +21,12 @@ You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
+/* FIXME: This is a temporary hack, so that we can include <algorithm>
+ below. <algorithm> will try to include <cstdlib> which will reference
+ malloc & co, which are poisoned by "system.h". The proper solution is
+ to include <cstdlib> in "system.h" instead of <stdlib.h>. */
+#include <cstdlib>
+
#include "config.h"
#include "system.h"
#include "coretypes.h"
@@ -56,6 +62,7 @@ along with GCC; see the file COPYING3. If not see
#include "tm-constrs.h"
#include "opts.h"
+#include <algorithm>
int code_for_indirect_jump_scratch = CODE_FOR_indirect_jump_scratch;
@@ -1791,65 +1798,124 @@ prepare_move_operands (rtx operands[], enum machine_mode mode)
}
}
-enum rtx_code
-prepare_cbranch_operands (rtx *operands, enum machine_mode mode,
- enum rtx_code comparison)
+/* Implement the CANONICALIZE_COMPARISON macro for the combine pass.
+ This function is also re-used to canonicalize comparisons in cbranch
+ pattern expanders. */
+void
+sh_canonicalize_comparison (enum rtx_code& cmp, rtx& op0, rtx& op1,
+ enum machine_mode mode)
{
- rtx op1;
- rtx scratch = NULL_RTX;
+ /* When invoked from within the combine pass the mode is not specified,
+ so try to get it from one of the operands. */
+ if (mode == VOIDmode)
+ mode = GET_MODE (op0);
+ if (mode == VOIDmode)
+ mode = GET_MODE (op1);
- if (comparison == LAST_AND_UNUSED_RTX_CODE)
- comparison = GET_CODE (operands[0]);
- else
- scratch = operands[4];
- if (CONST_INT_P (operands[1])
- && !CONST_INT_P (operands[2]))
- {
- rtx tmp = operands[1];
+ // We need to have a mode to do something useful here.
+ if (mode == VOIDmode)
+ return;
+
+ // Currently, we don't deal with floats here.
+ if (GET_MODE_CLASS (mode) == MODE_FLOAT)
+ return;
- operands[1] = operands[2];
- operands[2] = tmp;
- comparison = swap_condition (comparison);
+ // Make sure that the constant operand is the second operand.
+ if (CONST_INT_P (op0) && !CONST_INT_P (op1))
+ {
+ std::swap (op0, op1);
+ cmp = swap_condition (cmp);
}
- if (CONST_INT_P (operands[2]))
+
+ if (CONST_INT_P (op1))
{
- HOST_WIDE_INT val = INTVAL (operands[2]);
- if ((val == -1 || val == -0x81)
- && (comparison == GT || comparison == LE))
+ /* Try to adjust the constant operand in such a way that available
+ comparison insns can be utilized better and the constant can be
+ loaded with a 'mov #imm,Rm' insn. This avoids a load from the
+ constant pool. */
+ const HOST_WIDE_INT val = INTVAL (op1);
+
+ /* x > -1 --> x >= 0
+ x > 0xFFFFFF7F --> x >= 0xFFFFFF80
+ x <= -1 --> x < 0
+ x <= 0xFFFFFF7F --> x < 0xFFFFFF80 */
+ if ((val == -1 || val == -0x81) && (cmp == GT || cmp == LE))
+ {
+ cmp = cmp == GT ? GE : LT;
+ op1 = gen_int_mode (val + 1, mode);
+ }
+
+ /* x >= 1 --> x > 0
+ x >= 0x80 --> x > 0x7F
+ x < 1 --> x <= 0
+ x < 0x80 --> x <= 0x7F */
+ else if ((val == 1 || val == 0x80) && (cmp == GE || cmp == LT))
{
- comparison = (comparison == GT) ? GE : LT;
- operands[2] = gen_int_mode (val + 1, mode);
+ cmp = cmp == GE ? GT : LE;
+ op1 = gen_int_mode (val - 1, mode);
}
- else if ((val == 1 || val == 0x80)
- && (comparison == GE || comparison == LT))
+
+ /* unsigned x >= 1 --> x != 0
+ unsigned x < 1 --> x == 0 */
+ else if (val == 1 && (cmp == GEU || cmp == LTU))
{
- comparison = (comparison == GE) ? GT : LE;
- operands[2] = gen_int_mode (val - 1, mode);
+ cmp = cmp == GEU ? NE : EQ;
+ op1 = CONST0_RTX (mode);
}
- else if (val == 1 && (comparison == GEU || comparison == LTU))
+
+ /* unsigned x >= 0x80 --> unsigned x > 0x7F
+ unsigned x < 0x80 --> unsigned x < 0x7F */
+ else if (val == 0x80 && (cmp == GEU || cmp == LTU))
{
- comparison = (comparison == GEU) ? NE : EQ;
- operands[2] = CONST0_RTX (mode);
+ cmp = cmp == GEU ? GTU : LEU;
+ op1 = gen_int_mode (val - 1, mode);
}
- else if (val == 0x80 && (comparison == GEU || comparison == LTU))
+
+ /* unsigned x > 0 --> x != 0
+ unsigned x <= 0 --> x == 0 */
+ else if (val == 0 && (cmp == GTU || cmp == LEU))
+ cmp = cmp == GTU ? NE : EQ;
+
+ /* unsigned x > 0x7FFFFFFF --> signed x < 0
+ unsigned x <= 0x7FFFFFFF --> signed x >= 0 */
+ else if (mode == SImode && (cmp == GTU || cmp == LEU)
+ && val == 0x7FFFFFFF)
{
- comparison = (comparison == GEU) ? GTU : LEU;
- operands[2] = gen_int_mode (val - 1, mode);
+ cmp = cmp == GTU ? LT : GE;
+ op1 = const0_rtx;
}
- else if (val == 0 && (comparison == GTU || comparison == LEU))
- comparison = (comparison == GTU) ? NE : EQ;
- else if (mode == SImode
- && ((val == 0x7fffffff
- && (comparison == GTU || comparison == LEU))
- || ((unsigned HOST_WIDE_INT) val
- == (unsigned HOST_WIDE_INT) 0x7fffffff + 1
- && (comparison == GEU || comparison == LTU))))
+
+ /* unsigned x >= 0x80000000 --> signed x < 0
+ unsigned x < 0x80000000 --> signed x >= 0 */
+ else if (mode == SImode && (cmp == GEU || cmp == LTU)
+ && (unsigned HOST_WIDE_INT)val
+ == ((unsigned HOST_WIDE_INT)0x7FFFFFFF + 1))
{
- comparison = (comparison == GTU || comparison == GEU) ? LT : GE;
- operands[2] = CONST0_RTX (mode);
+ cmp = cmp == GEU ? LT : GE;
+ op1 = const0_rtx;
}
}
- op1 = operands[1];
+}
+
+enum rtx_code
+prepare_cbranch_operands (rtx *operands, enum machine_mode mode,
+ enum rtx_code comparison)
+{
+ /* The scratch reg is only available when this is invoked from within
+ the cbranchdi4_i splitter, through expand_cbranchdi4. */
+ rtx scratch = NULL_RTX;
+
+ if (comparison == LAST_AND_UNUSED_RTX_CODE)
+ comparison = GET_CODE (operands[0]);
+ else
+ scratch = operands[4];
+
+ sh_canonicalize_comparison (comparison, operands[1], operands[2], mode);
+
+ /* Notice that this function is also invoked after reload by
+ the cbranchdi4_i pattern, through expand_cbranchdi4. */
+ rtx op1 = operands[1];
+
if (can_create_pseudo_p ())
operands[1] = force_reg (mode, op1);
/* When we are handling DImode comparisons, we want to keep constants so
@@ -1883,8 +1949,6 @@ void
expand_cbranchsi4 (rtx *operands, enum rtx_code comparison, int probability)
{
rtx (*branch_expander) (rtx, rtx) = gen_branch_true;
- rtx jump;
-
comparison = prepare_cbranch_operands (operands, SImode, comparison);
switch (comparison)
{
@@ -1896,10 +1960,9 @@ expand_cbranchsi4 (rtx *operands, enum rtx_code comparison, int probability)
emit_insn (gen_rtx_SET (VOIDmode, get_t_reg_rtx (),
gen_rtx_fmt_ee (comparison, SImode,
operands[1], operands[2])));
- jump = emit_jump_insn (branch_expander (operands[3], get_t_reg_rtx ()));
+ rtx jump = emit_jump_insn (branch_expander (operands[3], get_t_reg_rtx ()));
if (probability >= 0)
add_reg_note (jump, REG_BR_PROB, GEN_INT (probability));
-
}
/* ??? How should we distribute probabilities when more than one branch
@@ -1956,8 +2019,7 @@ expand_cbranchdi4 (rtx *operands, enum rtx_code comparison)
lsw_taken = EQ;
if (prob >= 0)
{
- /* If we had more precision, we'd use rev_prob - (rev_prob >> 32) .
- */
+ // If we had more precision, we'd use rev_prob - (rev_prob >> 32) .
msw_skip_prob = rev_prob;
if (REG_BR_PROB_BASE <= 65535)
lsw_taken_prob = prob ? REG_BR_PROB_BASE : 0;
diff --git a/gcc/config/sh/sh.h b/gcc/config/sh/sh.h
index af7fe0bf545e..b36287276aa5 100644
--- a/gcc/config/sh/sh.h
+++ b/gcc/config/sh/sh.h
@@ -1946,6 +1946,10 @@ struct sh_args {
leave this zero for correct SH3 code. */
#define SHIFT_COUNT_TRUNCATED (! TARGET_SH3 && ! TARGET_SH2A)
+/* CANONICALIZE_COMPARISON macro for the combine pass. */
+#define CANONICALIZE_COMPARISON(CODE, OP0, OP1) \
+ sh_canonicalize_comparison ((CODE), (OP0), (OP1))
+
/* All integers have the same format so truncation is easy. */
/* But SHmedia must sign-extend DImode when truncating to SImode. */
#define TRULY_NOOP_TRUNCATION(OUTPREC,INPREC) \
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index d69d2947ebbd..8b44fbda4965 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -881,10 +881,9 @@
if (TARGET_SHMEDIA)
emit_jump_insn (gen_cbranchint4_media (operands[0], operands[1],
operands[2], operands[3]));
- else if (TARGET_CBRANCHDI4)
- expand_cbranchsi4 (operands, LAST_AND_UNUSED_RTX_CODE, -1);
else
- sh_emit_compare_and_branch (operands, SImode);
+ expand_cbranchsi4 (operands, LAST_AND_UNUSED_RTX_CODE, -1);
+
DONE;
})
--
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