This patch extracts a cc comparison from the initial compare/jump
insn and allows it to be passed to noce_emit_cmove and
emit_conditional_move.
---
gcc/ifcvt.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++----
gcc/optabs.c | 7 ++++--
gcc/optabs.h | 2 +-
3 files changed, 69 insertions(+), 8 deletions(-)
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 99716e5f63c..3db707e1fd1 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -86,6 +86,7 @@ static rtx_insn *find_active_insn_after (basic_block,
rtx_insn *);
static basic_block block_fallthru (basic_block);
static rtx cond_exec_get_condition (rtx_insn *);
static rtx noce_get_condition (rtx_insn *, rtx_insn **, bool);
+static rtx noce_get_compare (rtx_insn *, bool);
static int noce_operand_ok (const_rtx);
static void merge_if_block (ce_if_block *);
static int find_cond_trap (basic_block, edge, edge);
@@ -775,7 +776,7 @@ static int noce_try_addcc (struct noce_if_info *);
static int noce_try_store_flag_constants (struct noce_if_info *);
static int noce_try_store_flag_mask (struct noce_if_info *);
static rtx noce_emit_cmove (struct noce_if_info *, rtx, enum rtx_code, rtx,
- rtx, rtx, rtx);
+ rtx, rtx, rtx, rtx = NULL);
static int noce_try_cmove (struct noce_if_info *);
static int noce_try_cmove_arith (struct noce_if_info *);
static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx_insn **);
@@ -1658,7 +1659,7 @@ noce_try_store_flag_mask (struct noce_if_info *if_info)
static rtx
noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
- rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue)
+ rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue, rtx cc_cmp)
{
rtx target ATTRIBUTE_UNUSED;
int unsignedp ATTRIBUTE_UNUSED;
@@ -1706,7 +1707,7 @@ noce_emit_cmove (struct noce_if_info *if_info, rtx x,
enum rtx_code code,
target = emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
vtrue, vfalse, GET_MODE (x),
- unsignedp);
+ unsignedp, cc_cmp);
if (target)
return target;
@@ -2970,6 +2971,60 @@ noce_get_condition (rtx_insn *jump, rtx_insn **earliest,
bool then_else_reversed
return tmp;
}
+/* Get the comparison from the insn. */
+static rtx
+noce_get_compare (rtx_insn *jump, bool then_else_reversed)
+{
+ enum rtx_code code;
+ const_rtx set;
+ rtx tem;
+ rtx op0, op1;
+
+ if (!have_cbranchcc4)
+ return 0;
+
+ if (! any_condjump_p (jump))
+ return NULL_RTX;
+
+ set = pc_set (jump);
+
+ /* If this branches to JUMP_LABEL when the condition is false,
+ reverse the condition. */
+ bool reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
+ && label_ref_label (XEXP (SET_SRC (set), 2)) == JUMP_LABEL (jump));
+
+ /* We may have to reverse because the caller's if block is not canonical,
+ i.e. the THEN block isn't the fallthrough block for the TEST block
+ (see find_if_header). */
+ if (then_else_reversed)
+ reverse = !reverse;
+
+ rtx cond = XEXP (SET_SRC (set), 0);
+
+ code = GET_CODE (cond);
+ op0 = XEXP (cond, 0);
+ op1 = XEXP (cond, 1);
+
+ if (reverse)
+ code = reversed_comparison_code (cond, jump);
+ if (code == UNKNOWN)
+ return 0;
+
+ /* If constant is first, put it last. */
+ if (CONSTANT_P (op0))
+ code = swap_condition (code), tem = op0, op0 = op1, op1 = tem;
+
+ /* Never return CC0; return zero instead. */
+ if (CC0_P (op0))
+ return 0;
+
+ /* We promised to return a comparison. */
+ rtx ret = gen_rtx_fmt_ee (code, VOIDmode, op0, op1);
+ if (COMPARISON_P (ret))
+ return ret;
+ return 0;
+}
+
/* Return true if OP is ok for if-then-else processing. */
static int
@@ -3140,6 +3195,8 @@ noce_convert_multiple_sets (struct noce_if_info *if_info)
rtx y = XEXP (cond, 1);
rtx_code cond_code = GET_CODE (cond);
+ rtx cc_cmp = noce_get_compare (jump, false);
+
/* The true targets for a conditional move. */
auto_vec<rtx> targets;
/* The temporaries introduced to allow us to not consider register
@@ -3151,7 +3208,8 @@ noce_convert_multiple_sets (struct noce_if_info *if_info)
hash_map<rtx, bool> need_temps;
- check_need_temps (then_bb, &need_temps, cond);
+ if (!cc_cmp)
+ check_need_temps (then_bb, &need_temps, cond);
hash_map<rtx, bool> temps_created;
@@ -3242,7 +3300,7 @@ noce_convert_multiple_sets (struct noce_if_info *if_info)
/* Actually emit the conditional move. */
rtx temp_dest = noce_emit_cmove (if_info, temp, cond_code,
- x, y, new_val, old_val);
+ x, y, new_val, old_val, cc_cmp);
/* If we failed to expand the conditional move, drop out and don't
try to continue. */
diff --git a/gcc/optabs.c b/gcc/optabs.c
index 06bcaab1f55..3ce6f8cdd30 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -4325,7 +4325,7 @@ emit_indirect_jump (rtx loc)
rtx
emit_conditional_move (rtx target, enum rtx_code code, rtx op0, rtx op1,
machine_mode cmode, rtx op2, rtx op3,
- machine_mode mode, int unsignedp)
+ machine_mode mode, int unsignedp, rtx cc_cmp)
{
rtx comparison;
rtx_insn *last;
@@ -4408,7 +4408,10 @@ emit_conditional_move (rtx target, enum rtx_code code,
rtx op0, rtx op1,
class expand_operand ops[4];
create_output_operand (&ops[0], target, mode);
- create_fixed_operand (&ops[1], comparison);
+ if (cc_cmp)
+ create_fixed_operand (&ops[1], cc_cmp);
+ else
+ create_fixed_operand (&ops[1], comparison);
create_input_operand (&ops[2], op2, mode);
create_input_operand (&ops[3], op3, mode);
if (maybe_expand_insn (icode, 4, ops))
diff --git a/gcc/optabs.h b/gcc/optabs.h
index 0654107d6e3..c4540f87144 100644
--- a/gcc/optabs.h
+++ b/gcc/optabs.h
@@ -258,7 +258,7 @@ extern void emit_indirect_jump (rtx);
/* Emit a conditional move operation. */
rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, machine_mode,
- rtx, rtx, machine_mode, int);
+ rtx, rtx, machine_mode, int, rtx = NULL);
/* Emit a conditional negate or bitwise complement operation. */
rtx emit_conditional_neg_or_complement (rtx, rtx_code, machine_mode, rtx,
--
2.17.0
