re PR target/51244 ([SH] Inefficient conditional branch and code around T bit)

gcc/
	PR target/51244
	* config/sh/sh_treg_combine.cc (is_conditional_insn): New function.
	(cbranch_trace): Add member rtx* condition_rtx_in_insn, initialize it
	accordingly in constructor.
	(cbranch_trace::branch_condition_rtx_ref): New function.
	(cbranch_trace::branch_condition_rtx): Use branch_condition_rtx_ref.
	(sh_treg_combine::try_invert_branch_condition): Invert condition rtx
	in insn using reversed_comparison_code and validate_change instead of
	invert_jump_1.
	(sh_treg_combine::execute): Look for conditional insns in basic blocks
	in addition to conditional branches.
	* config/sh/sh.md (*movsicc_div0s): Remove combine patterns.

From-SVN: r218850

3 files changed, 69 insertions, 49 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 00b3728..f9e1af5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,21 @@
 2014-12-17  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	PR target/51244
+	* config/sh/sh_treg_combine.cc (is_conditional_insn): New function.
+	(cbranch_trace): Add member rtx* condition_rtx_in_insn, initialize it
+	accordingly in constructor.
+	(cbranch_trace::branch_condition_rtx_ref): New function.
+	(cbranch_trace::branch_condition_rtx): Use branch_condition_rtx_ref.
+	(sh_treg_combine::try_invert_branch_condition): Invert condition rtx
+	in insn using reversed_comparison_code and validate_change instead of
+	invert_jump_1.
+	(sh_treg_combine::execute): Look for conditional insns in basic blocks
+	in addition to conditional branches.
+	* config/sh/sh.md (*movsicc_div0s): Remove combine patterns.
+
+2014-12-17  Oleg Endo  <olegendo@gcc.gnu.org>
+
+	PR target/51244
 	* config/sh/sh_treg_combine.cc (sh_treg_combine::try_optimize_cbranch):
 	Combine ccreg inversion and cbranch into inverted cbranch.
 
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 644dd06..5aa50a25 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -1086,47 +1086,6 @@
 		      (label_ref (match_dup 2))
 		      (pc)))])
 
-;; Conditional move combine pattern for div0s comparisons.
-;; This is used when TARGET_PRETEND_CMOVE is in effect.
-(define_insn_and_split "*movsicc_div0s"
-  [(set (match_operand:SI 0 "arith_reg_dest" "")
-	(if_then_else:SI (ge (xor:SI (match_operand:SI 1 "arith_reg_operand" "")
-				     (match_operand:SI 2 "arith_reg_operand" ""))
-			     (const_int 0))
-			 (match_operand:SI 3 "arith_reg_operand" "")
-			 (match_operand:SI 4 "general_movsrc_operand" "")))
-   (clobber (reg:SI T_REG))]
-  "TARGET_PRETEND_CMOVE"
-  "#"
-  "&& 1"
-  [(set (reg:SI T_REG) (lt:SI (xor:SI (match_dup 1) (match_dup 2))
-			      (const_int 0)))
-   (set (match_dup 0)
-	(if_then_else (ne (reg:SI T_REG) (const_int 0))
-		      (match_dup 4)
-		      (match_dup 3)))])
-
-(define_insn_and_split "*movsicc_div0s"
-  [(set (match_operand:SI 0 "arith_reg_dest")
-	(if_then_else:SI (eq (lshiftrt:SI
-				(match_operand:SI 1 "arith_reg_operand")
-				(const_int 31))
-			     (lshiftrt:SI
-				(match_operand:SI 2 "arith_reg_operand")
-				(const_int 31)))
-			 (match_operand:SI 3 "arith_reg_operand")
-			 (match_operand:SI 4 "general_movsrc_operand")))
-   (clobber (reg:SI T_REG))]
-   "TARGET_PRETEND_CMOVE"
-   "#"
-   "&& 1"
-  [(set (reg:SI T_REG) (lt:SI (xor:SI (match_dup 1) (match_dup 2))
-			      (const_int 0)))
-   (set (match_dup 0)
-	(if_then_else (ne (reg:SI T_REG) (const_int 0))
-		      (match_dup 4)
-		      (match_dup 3)))])
-
 ;; -------------------------------------------------------------------------
 ;; SImode unsigned integer comparisons
 ;; -------------------------------------------------------------------------
diff --git a/gcc/config/sh/sh_treg_combine.cc b/gcc/config/sh/sh_treg_combine.cc
index 62392d8..97e677d 100644
--- a/gcc/config/sh/sh_treg_combine.cc
+++ b/gcc/config/sh/sh_treg_combine.cc
@@ -432,6 +432,16 @@ trace_reg_uses (rtx reg, rtx_insn *start_insn, rtx abort_at_insn)
   return count;
 }
 
+static bool
+is_conditional_insn (rtx_insn* i)
+{
+  if (! (INSN_P (i) && NONDEBUG_INSN_P (i)))
+    return false;
+
+  rtx p = PATTERN (i);
+  return GET_CODE (p) == SET && GET_CODE (XEXP (p, 1)) == IF_THEN_ELSE;
+}
+
 // FIXME: Remove dependency on SH predicate function somehow.
 extern int t_reg_operand (rtx, machine_mode);
 extern int negt_reg_operand (rtx, machine_mode);
@@ -484,6 +494,7 @@ private:
   struct cbranch_trace
   {
     rtx_insn *cbranch_insn;
+    rtx* condition_rtx_in_insn;
     branch_condition_type_t cbranch_type;
 
     // The comparison against zero right before the conditional branch.
@@ -495,9 +506,14 @@ private:
 
     cbranch_trace (rtx_insn *insn)
     : cbranch_insn (insn),
+      condition_rtx_in_insn (NULL),
       cbranch_type (unknown_branch_condition),
       setcc ()
     {
+      if (is_conditional_insn (cbranch_insn))
+	condition_rtx_in_insn = &XEXP (XEXP (PATTERN (cbranch_insn), 1), 0);
+      else if (rtx x = pc_set (cbranch_insn))
+	condition_rtx_in_insn = &XEXP (XEXP (x, 1), 0);
     }
 
     basic_block bb (void) const { return BLOCK_FOR_INSN (cbranch_insn); }
@@ -505,8 +521,16 @@ private:
     rtx
     branch_condition_rtx (void) const
     {
-      rtx x = pc_set (cbranch_insn);
-      return x == NULL_RTX ? NULL_RTX : XEXP (XEXP (x, 1), 0);
+      return condition_rtx_in_insn != NULL ? *condition_rtx_in_insn : NULL;
+    }
+    rtx&
+    branch_condition_rtx_ref (void) const
+    {
+      // Before anything gets to invoke this function, there are other checks
+      // in place to make sure that we have a known branch condition and thus
+      // the ref to the rtx in the insn.
+      gcc_assert (condition_rtx_in_insn != NULL);
+      return *condition_rtx_in_insn;
     }
 
     bool
@@ -1033,8 +1057,18 @@ sh_treg_combine::try_invert_branch_condition (cbranch_trace& trace)
 {
   log_msg ("inverting branch condition\n");
 
-  if (!invert_jump_1 (trace.cbranch_insn, JUMP_LABEL (trace.cbranch_insn)))
-    log_return (false, "invert_jump_1 failed\n");
+  rtx& comp = trace.branch_condition_rtx_ref ();
+
+  rtx_code rev_cmp_code = reversed_comparison_code (comp, trace.cbranch_insn);
+
+  if (rev_cmp_code == UNKNOWN)
+    log_return (false, "reversed_comparison_code = UNKNOWN\n");
+
+  validate_change (trace.cbranch_insn, &comp,
+		   gen_rtx_fmt_ee (rev_cmp_code,
+				   GET_MODE (comp), XEXP (comp, 0),
+				   XEXP (comp, 1)),
+		   1);
 
   if (verify_changes (num_validated_changes ()))
     confirm_change_group ();
@@ -1531,14 +1565,26 @@ sh_treg_combine::execute (function *fun)
   log_rtx (m_ccreg);
   log_msg ("  STORE_FLAG_VALUE = %d\n", STORE_FLAG_VALUE);
 
-  // Look for basic blocks that end with a conditional branch and try to
-  // optimize them.
+  // Look for basic blocks that end with a conditional branch or for
+  // conditional insns and try to optimize them.
   basic_block bb;
   FOR_EACH_BB_FN (bb, fun)
     {
-      rtx_insn *i = BB_END (bb);
+      rtx_insn* i = BB_END (bb);
+      if (i == NULL || i == PREV_INSN (BB_HEAD (bb)))
+	continue;
+
+      // A conditional branch is always the last insn of a basic block.
       if (any_condjump_p (i) && onlyjump_p (i))
-	try_optimize_cbranch (i);
+	{
+	  try_optimize_cbranch (i);
+	  i = PREV_INSN (i);
+	}
+
+      // Check all insns in block for conditional insns.
+      for (; i != NULL && i != PREV_INSN (BB_HEAD (bb)); i = PREV_INSN (i))
+	if (is_conditional_insn (i))
+	  try_optimize_cbranch (i);
     }
 
   log_msg ("\n\n");