profile-count.h (profile_probability::from_reg_br_prob_note, [...]): New functions.

	* profile-count.h (profile_probability::from_reg_br_prob_note,
	profile_probability::to_reg_br_prob_note): New functions.
	* doc/rtl.texi (REG_BR_PROB_NOTE): Update documentation.
	* reg-notes.h (REG_BR_PROB, REG_BR_PRED): Update docs.
	* predict.c (probability_reliable_p): Update.
	(edge_probability_reliable_p): Update.
	(br_prob_note_reliable_p): Update.
	(invert_br_probabilities): Update.
	(add_reg_br_prob_note): New function.
	(combine_predictions_for_insn): Update.
	* asan.c (asan_clear_shadow): Update.
	* cfgbuild.c (compute_outgoing_frequencies): Update.
	* cfgrtl.c (force_nonfallthru_and_redirect): Update.
	(update_br_prob_note): Update.
	(rtl_verify_edges): Update.
	(purge_dead_edges): Update.
	(fixup_reorder_chain): Update.
	* emit-rtl.c (try_split): Update.
	* ifcvt.c (cond_exec_process_insns): Update.
	(cond_exec_process_if_block): Update.
	(dead_or_predicable): Update.
	* internal-fn.c (expand_addsub_overflow): Update.
	(expand_neg_overflow): Update.
	(expand_mul_overflow): Update.
	* loop-doloop.c (doloop_modify): Update.
	* loop-unroll.c (compare_and_jump_seq): Update.
	* optabs.c (emit_cmp_and_jump_insn_1): Update.
	* predict.h: Update.
	* reorg.c (mostly_true_jump): Update.
	* rtl.h: Update.
	* config/aarch64/aarch64.c (aarch64_emit_unlikely_jump): Update.
	* config/alpha/alpha.c (emit_unlikely_jump): Update.
	* config/arc/arc.c: (emit_unlikely_jump): Update.
	* config/arm/arm.c: (emit_unlikely_jump): Update.
	* config/bfin/bfin.c (cbranch_predicted_taken_p): Update.
	* config/frv/frv.c (frv_print_operand_jump_hint): Update.
	* config/i386/i386.c (ix86_expand_split_stack_prologue): Update.
	(ix86_print_operand): Update.
	(ix86_split_fp_branch): Update.
	(predict_jump): Update.
	* config/ia64/ia64.c (ia64_print_operand): Update.
	* config/mmix/mmix.c (mmix_print_operand): Update.
	* config/powerpcspe/powerpcspe.c (output_cbranch): Update.
	(rs6000_expand_split_stack_prologue): Update.
	* config/rs6000/rs6000.c: Update.
	* config/s390/s390.c (s390_expand_vec_strlen): Update.
	(s390_expand_vec_movstr): Update.
	(s390_expand_cs_tdsi): Update.
	(s390_expand_split_stack_prologue): Update.
	* config/sh/sh.c (sh_print_operand): Update.
	(expand_cbranchsi4): Update.
	(expand_cbranchdi4): Update.
	* config/sparc/sparc.c (output_v9branch): Update.
	* config/spu/spu.c (get_branch_target): Update.
	(ea_load_store_inline): Update.
	* config/tilegx/tilegx.c (cbranch_predicted_p): Update.
	* config/tilepro/tilepro.c: Update.
	* gcc.dg/predict-8.c: Update.

From-SVN: r250239

19 files changed, 86 insertions, 85 deletions

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 134d37b..b8a4160 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -12161,10 +12161,8 @@ aarch64_emit_store_exclusive (machine_mode mode, rtx bval,
 static void
 aarch64_emit_unlikely_jump (rtx insn)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
-
   rtx_insn *jump = emit_jump_insn (insn);
-  add_int_reg_note (jump, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (jump, profile_probability::very_unlikely ());
 }
 
 /* Expand a compare and swap pattern.  */
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index 00a69c1..1114e66 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -4319,10 +4319,9 @@ alpha_expand_builtin_vector_binop (rtx (*gen) (rtx, rtx, rtx),
 static void
 emit_unlikely_jump (rtx cond, rtx label)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
   rtx x = gen_rtx_IF_THEN_ELSE (VOIDmode, cond, label, pc_rtx);
   rtx_insn *insn = emit_jump_insn (gen_rtx_SET (pc_rtx, x));
-  add_int_reg_note (insn, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (insn, profile_probability::very_unlikely ());
 }
 
 /* A subroutine of the atomic operation splitters.  Emit a load-locked
diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index ed8fd8e..a92ee4c 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -9979,10 +9979,8 @@ arc_post_atomic_barrier (enum memmodel model)
 static void
 emit_unlikely_jump (rtx insn)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
-
   rtx_insn *jump = emit_jump_insn (insn);
-  add_int_reg_note (jump, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (jump, profile_probability::very_unlikely ());
 }
 
 /* Expand code to perform a 8 or 16-bit compare and swap by doing
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index f59132c..1b7b382 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -28271,7 +28271,7 @@ emit_unlikely_jump (rtx insn)
   int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
 
   rtx_insn *jump = emit_jump_insn (insn);
-  add_int_reg_note (jump, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (jump, profile_probability::very_unlikely ());
 }
 
 /* Expand a compare and swap pattern.  */
diff --git a/gcc/config/bfin/bfin.c b/gcc/config/bfin/bfin.c
index 2073927..9fe90fc 100644
--- a/gcc/config/bfin/bfin.c
+++ b/gcc/config/bfin/bfin.c
@@ -2435,9 +2435,8 @@ cbranch_predicted_taken_p (rtx insn)
 
   if (x)
     {
-      int pred_val = XINT (x, 0);
-
-      return pred_val >= REG_BR_PROB_BASE / 2;
+      return profile_probability::from_reg_br_prob_note (XINT (x, 0))
+	     >= profile_probability::even ();
     }
 
   return 0;
diff --git a/gcc/config/frv/frv.c b/gcc/config/frv/frv.c
index 0918b98..c571d63 100644
--- a/gcc/config/frv/frv.c
+++ b/gcc/config/frv/frv.c
@@ -2621,7 +2621,6 @@ frv_print_operand_jump_hint (rtx_insn *insn)
   rtx note;
   rtx labelref;
   int ret;
-  int prob = -1;
   enum { UNKNOWN, BACKWARD, FORWARD } jump_type = UNKNOWN;
 
   gcc_assert (JUMP_P (insn));
@@ -2647,8 +2646,8 @@ frv_print_operand_jump_hint (rtx_insn *insn)
 
       else
 	{
-	  prob = XINT (note, 0);
-	  ret = ((prob >= (REG_BR_PROB_BASE / 2))
+	  ret = ((profile_probability::from_reg_br_prob_note (XINT (note, 0))
+		  >= profile_probability::even ())
 		 ? FRV_JUMP_LIKELY
 		 : FRV_JUMP_NOT_LIKELY);
 	}
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 42e0dda..eac7681 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -15783,8 +15783,7 @@ ix86_expand_split_stack_prologue (void)
   JUMP_LABEL (jump_insn) = label;
 
   /* Mark the jump as very likely to be taken.  */
-  add_int_reg_note (jump_insn, REG_BR_PROB,
-		    REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100);
+  add_reg_br_prob_note (jump_insn, profile_probability::very_likely ());
 
   if (split_stack_fn == NULL_RTX)
     {
@@ -19128,7 +19127,8 @@ ix86_print_operand (FILE *file, rtx x, int code)
 	    x = find_reg_note (current_output_insn, REG_BR_PROB, 0);
 	    if (x)
 	      {
-		int pred_val = XINT (x, 0);
+		int pred_val = profile_probability::from_reg_br_prob_note
+				 (XINT (x, 0)).to_reg_br_prob_base ();
 
 		if (pred_val < REG_BR_PROB_BASE * 45 / 100
 		    || pred_val > REG_BR_PROB_BASE * 55 / 100)
@@ -23865,8 +23865,8 @@ ix86_split_fp_branch (enum rtx_code code, rtx op1, rtx op2,
 		      (pc_rtx,
 		       gen_rtx_IF_THEN_ELSE (VOIDmode,
 					     condition, target1, target2)));
-  if (split_branch_probability >= 0)
-    add_int_reg_note (i, REG_BR_PROB, split_branch_probability);
+  if (split_branch_probability.initialized_p ())
+    add_reg_br_prob_note (i, split_branch_probability);
 }
 
 void
@@ -26911,7 +26911,7 @@ predict_jump (int prob)
 {
   rtx_insn *insn = get_last_insn ();
   gcc_assert (JUMP_P (insn));
-  add_int_reg_note (insn, REG_BR_PROB, prob);
+  add_reg_br_prob_note (insn, profile_probability::from_reg_br_prob_base (prob));
 }
 
 /* Helper function for the string operations below.  Dest VARIABLE whether
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index 617d188..c8e4c74 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -5502,7 +5502,8 @@ ia64_print_operand (FILE * file, rtx x, int code)
 	x = find_reg_note (current_output_insn, REG_BR_PROB, 0);
 	if (x)
 	  {
-	    int pred_val = XINT (x, 0);
+	    int pred_val = profile_probability::from_reg_br_prob_note
+				 (XINT (x, 0)).to_reg_br_prob_base ();
 
 	    /* Guess top and bottom 10% statically predicted.  */
 	    if (pred_val < REG_BR_PROB_BASE / 50
diff --git a/gcc/config/mmix/mmix.c b/gcc/config/mmix/mmix.c
index 3278688..9849c19 100644
--- a/gcc/config/mmix/mmix.c
+++ b/gcc/config/mmix/mmix.c
@@ -1536,7 +1536,8 @@ mmix_print_operand (FILE *stream, rtx x, int code)
       if (TARGET_BRANCH_PREDICT)
 	{
 	  x = find_reg_note (current_output_insn, REG_BR_PROB, 0);
-	  if (x && XINT (x, 0) > REG_BR_PROB_BASE / 2)
+	  if (x && profile_probability::from_reg_br_prob_note (XINT (x, 0))
+	      > profile_probability::even ())
 	    putc ('P', stream);
 	}
       return;
diff --git a/gcc/config/powerpcspe/powerpcspe.c b/gcc/config/powerpcspe/powerpcspe.c
index 06d66d7..b94afd5 100644
--- a/gcc/config/powerpcspe/powerpcspe.c
+++ b/gcc/config/powerpcspe/powerpcspe.c
@@ -25333,7 +25333,8 @@ output_cbranch (rtx op, const char *label, int reversed, rtx_insn *insn)
   if (note != NULL_RTX)
     {
       /* PROB is the difference from 50%.  */
-      int prob = XINT (note, 0) - REG_BR_PROB_BASE / 2;
+      int prob = profile_probability::from_reg_br_prob_note (XINT (note, 0))
+		   .to_reg_br_prob_base () - REG_BR_PROB_BASE / 2;
 
       /* Only hint for highly probable/improbable branches on newer cpus when
 	 we have real profile data, as static prediction overrides processor
@@ -26123,10 +26124,9 @@ rs6000_split_signbit (rtx dest, rtx src)
 static void
 emit_unlikely_jump (rtx cond, rtx label)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
   rtx x = gen_rtx_IF_THEN_ELSE (VOIDmode, cond, label, pc_rtx);
   rtx_insn *insn = emit_jump_insn (gen_rtx_SET (pc_rtx, x));
-  add_int_reg_note (insn, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (insn, profile_probability::very_unlikely ());
 }
 
 /* A subroutine of the atomic operation splitters.  Emit a load-locked
@@ -32192,8 +32192,7 @@ rs6000_expand_split_stack_prologue (void)
   insn = emit_jump_insn (gen_rtx_SET (pc_rtx, jump));
   JUMP_LABEL (insn) = ok_label;
   /* Mark the jump as very likely to be taken.  */
-  add_int_reg_note (insn, REG_BR_PROB,
-		    REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100);
+  add_reg_br_prob_note (insn, profile_probability::very_likely ());
 
   lr = gen_rtx_REG (Pmode, LR_REGNO);
   insn = emit_move_insn (r0, lr);
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 9bf6f37..e49a091 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -22759,7 +22759,8 @@ output_cbranch (rtx op, const char *label, int reversed, rtx_insn *insn)
   if (note != NULL_RTX)
     {
       /* PROB is the difference from 50%.  */
-      int prob = XINT (note, 0) - REG_BR_PROB_BASE / 2;
+      int prob = profile_probability::from_reg_br_prob_note (XINT (note, 0))
+		   .to_reg_br_prob_base () - REG_BR_PROB_BASE / 2;
 
       /* Only hint for highly probable/improbable branches on newer cpus when
 	 we have real profile data, as static prediction overrides processor
@@ -23528,10 +23529,9 @@ rs6000_split_signbit (rtx dest, rtx src)
 static void
 emit_unlikely_jump (rtx cond, rtx label)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
   rtx x = gen_rtx_IF_THEN_ELSE (VOIDmode, cond, label, pc_rtx);
   rtx_insn *insn = emit_jump_insn (gen_rtx_SET (pc_rtx, x));
-  add_int_reg_note (insn, REG_BR_PROB, very_unlikely);
+  add_reg_br_prob_note (insn, profile_probability::very_unlikely ());
 }
 
 /* A subroutine of the atomic operation splitters.  Emit a load-locked
@@ -29284,8 +29284,7 @@ rs6000_expand_split_stack_prologue (void)
   insn = emit_jump_insn (gen_rtx_SET (pc_rtx, jump));
   JUMP_LABEL (insn) = ok_label;
   /* Mark the jump as very likely to be taken.  */
-  add_int_reg_note (insn, REG_BR_PROB,
-		    REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100);
+  add_reg_br_prob_note (insn, profile_probability::very_likely ());
 
   lr = gen_rtx_REG (Pmode, LR_REGNO);
   insn = emit_move_insn (r0, lr);
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 31ced21..bbae89b 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -5720,8 +5720,6 @@ s390_emit_ccraw_jump (HOST_WIDE_INT mask, enum rtx_code comparison, rtx label)
 void
 s390_expand_vec_strlen (rtx target, rtx string, rtx alignment)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
-  int very_likely = REG_BR_PROB_BASE - 1;
   rtx highest_index_to_load_reg = gen_reg_rtx (Pmode);
   rtx str_reg = gen_reg_rtx (V16QImode);
   rtx str_addr_base_reg = gen_reg_rtx (Pmode);
@@ -5792,7 +5790,8 @@ s390_expand_vec_strlen (rtx target, rtx string, rtx alignment)
 				  GEN_INT (VSTRING_FLAG_ZS | VSTRING_FLAG_CS)));
 
   add_int_reg_note (s390_emit_ccraw_jump (8, NE, loop_start_label),
-		    REG_BR_PROB, very_likely);
+		    REG_BR_PROB,
+		    profile_probability::very_likely ().to_reg_br_prob_note ());
   emit_insn (gen_vec_extractv16qi (len, result_reg, GEN_INT (7)));
 
   /* If the string pointer wasn't aligned we have loaded less then 16
@@ -5812,8 +5811,8 @@ s390_expand_vec_strlen (rtx target, rtx string, rtx alignment)
     emit_insn (gen_movsicc (str_idx_reg, cond,
 			    highest_index_to_load_reg, str_idx_reg));
 
-  add_int_reg_note (s390_emit_jump (is_aligned_label, cond), REG_BR_PROB,
-		    very_unlikely);
+  add_reg_br_prob_note (s390_emit_jump (is_aligned_label, cond),
+		        profile_probability::very_unlikely ());
 
   expand_binop (Pmode, add_optab, str_idx_reg,
 		GEN_INT (-16), str_idx_reg, 1, OPTAB_DIRECT);
@@ -5829,7 +5828,6 @@ s390_expand_vec_strlen (rtx target, rtx string, rtx alignment)
 void
 s390_expand_vec_movstr (rtx result, rtx dst, rtx src)
 {
-  int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
   rtx temp = gen_reg_rtx (Pmode);
   rtx src_addr = XEXP (src, 0);
   rtx dst_addr = XEXP (dst, 0);
@@ -5906,7 +5904,8 @@ s390_expand_vec_movstr (rtx result, rtx dst, rtx src)
   emit_insn (gen_vec_vfenesv16qi (vpos, vsrc, vsrc,
 				  GEN_INT (VSTRING_FLAG_ZS | VSTRING_FLAG_CS)));
   add_int_reg_note (s390_emit_ccraw_jump (8, EQ, done_label),
-		    REG_BR_PROB, very_unlikely);
+		    REG_BR_PROB, profile_probability::very_unlikely ()
+				  .to_reg_br_prob_note ());
 
   emit_move_insn (gen_rtx_MEM (V16QImode,
 			       gen_rtx_PLUS (Pmode, dst_addr_reg, offset)),
@@ -6929,7 +6928,6 @@ s390_expand_cs_tdsi (machine_mode mode, rtx btarget, rtx vtarget, rtx mem,
 
   if (do_const_opt)
     {
-      const int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
       rtx cc = gen_rtx_REG (CCZmode, CC_REGNUM);
 
       skip_cs_label = gen_label_rtx ();
@@ -6950,7 +6948,8 @@ s390_expand_cs_tdsi (machine_mode mode, rtx btarget, rtx vtarget, rtx mem,
 	  emit_insn (gen_rtx_SET (cc, gen_rtx_COMPARE (CCZmode, output, cmp)));
 	}
       s390_emit_jump (skip_cs_label, gen_rtx_NE (VOIDmode, cc, const0_rtx));
-      add_int_reg_note (get_last_insn (), REG_BR_PROB, very_unlikely);
+      add_reg_br_prob_note (get_last_insn (), 
+		            profile_probability::very_unlikely ());
       /* If the jump is not taken, OUTPUT is the expected value.  */
       cmp = output;
       /* Reload newval to a register manually, *after* the compare and jump
@@ -11678,7 +11677,8 @@ s390_expand_split_stack_prologue (void)
       LABEL_NUSES (call_done)++;
 
       /* Mark the jump as very unlikely to be taken.  */
-      add_int_reg_note (insn, REG_BR_PROB, REG_BR_PROB_BASE / 100);
+      add_reg_br_prob_note (insn, 
+		            profile_probability::very_unlikely ());
 
       if (cfun->machine->split_stack_varargs_pointer != NULL_RTX)
 	{
diff --git a/gcc/config/sh/sh-protos.h b/gcc/config/sh/sh-protos.h
index 59be4c0..305ab2c 100644
--- a/gcc/config/sh/sh-protos.h
+++ b/gcc/config/sh/sh-protos.h
@@ -68,7 +68,7 @@ extern bool sh_expand_strlen  (rtx *);
 extern void sh_expand_setmem (rtx *);
 extern enum rtx_code prepare_cbranch_operands (rtx *, machine_mode mode,
 					       enum rtx_code comparison);
-extern void expand_cbranchsi4 (rtx *operands, enum rtx_code comparison, int);
+extern void expand_cbranchsi4 (rtx *operands, enum rtx_code comparison);
 extern bool expand_cbranchdi4 (rtx *operands, enum rtx_code comparison);
 extern void sh_emit_scc_to_t (enum rtx_code, rtx, rtx);
 extern void sh_emit_compare_and_branch (rtx *, machine_mode);
diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index ff79b93..6f01dcb 100644
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -1139,7 +1139,9 @@ sh_print_operand (FILE *stream, rtx x, int code)
       {
 	rtx note = find_reg_note (current_output_insn, REG_BR_PROB, 0);
 
-	if (note && XINT (note, 0) * 2 < REG_BR_PROB_BASE)
+	if (note
+	    && profile_probability::from_reg_br_prob_note (XINT (note, 0))
+	       < profile_probability::even ())
 	  fputs ("/u", stream);
 	break;
       }
@@ -1999,8 +2001,9 @@ prepare_cbranch_operands (rtx *operands, machine_mode mode,
   return comparison;
 }
 
-void
-expand_cbranchsi4 (rtx *operands, enum rtx_code comparison, int probability)
+static void
+expand_cbranchsi4 (rtx *operands, enum rtx_code comparison,
+		   profile_probability probability)
 {
   rtx (*branch_expander) (rtx) = gen_branch_true;
   comparison = prepare_cbranch_operands (operands, SImode, comparison);
@@ -2015,8 +2018,15 @@ expand_cbranchsi4 (rtx *operands, enum rtx_code comparison, int probability)
 			  gen_rtx_fmt_ee (comparison, SImode,
 					  operands[1], operands[2])));
   rtx_insn *jump = emit_jump_insn (branch_expander (operands[3]));
-  if (probability >= 0)
-    add_int_reg_note (jump, REG_BR_PROB, probability);
+  if (probability.initialized_p ())
+    add_reg_br_prob_note (jump, probability);
+}
+
+void
+expand_cbranchsi4 (rtx *operands, enum rtx_code comparison)
+{
+  expand_cbranchsi4 (operands, comparison,
+		     profile_probability::uninitialized ());
 }
 
 /* ??? How should we distribute probabilities when more than one branch
@@ -2043,8 +2053,10 @@ expand_cbranchdi4 (rtx *operands, enum rtx_code comparison)
   rtx_code_label *skip_label = NULL;
   rtx op1h, op1l, op2h, op2l;
   int num_branches;
-  int prob, rev_prob;
-  int msw_taken_prob = -1, msw_skip_prob = -1, lsw_taken_prob = -1;
+  profile_probability prob, rev_prob;
+  profile_probability msw_taken_prob = profile_probability::uninitialized (),
+		      msw_skip_prob = profile_probability::uninitialized (),
+		      lsw_taken_prob = profile_probability::uninitialized ();
 
   comparison = prepare_cbranch_operands (operands, DImode, comparison);
   op1h = gen_highpart_mode (SImode, DImode, operands[1]);
@@ -2053,34 +2065,28 @@ expand_cbranchdi4 (rtx *operands, enum rtx_code comparison)
   op2l = gen_lowpart (SImode, operands[2]);
   msw_taken = msw_skip = lsw_taken = LAST_AND_UNUSED_RTX_CODE;
   prob = split_branch_probability;
-  rev_prob = REG_BR_PROB_BASE - prob;
+  rev_prob = prob.invert ();
   switch (comparison)
     {
     case EQ:
       msw_skip = NE;
       lsw_taken = EQ;
-      if (prob >= 0)
+      if (prob.initialized_p ())
 	{
-	  // If we had more precision, we'd use rev_prob - (rev_prob >> 32) .
+	  /* FIXME: This is not optimal.  We do not really know the probablity
+	     that values differ by MCW only, but we should probably distribute
+	     probabilities more evenly.  */
 	  msw_skip_prob = rev_prob;
-	  if (REG_BR_PROB_BASE <= 65535)
-	    lsw_taken_prob = prob ? REG_BR_PROB_BASE : 0;
-	  else
-	    {
-	      lsw_taken_prob
-		= (prob
-		   ? (REG_BR_PROB_BASE
-		      - ((gcov_type) REG_BR_PROB_BASE * rev_prob
-			 / ((gcov_type) prob << 32)))
-		   : 0);
-	    }
+	  lsw_taken_prob = prob > profile_probability::never ()
+			   ? profile_probability::guessed_always ()
+			   : profile_probability::guessed_never ();
 	}
       break;
     case NE:
       msw_taken = NE;
       msw_taken_prob = prob;
       lsw_taken = NE;
-      lsw_taken_prob = 0;
+      lsw_taken_prob = profile_probability::guessed_never ();
       break;
     case GTU: case GT:
       msw_taken = comparison;
@@ -2133,18 +2139,20 @@ expand_cbranchdi4 (rtx *operands, enum rtx_code comparison)
   if (comparison != EQ && comparison != NE && num_branches > 1)
     {
       if (!CONSTANT_P (operands[2])
-	  && prob >= (int) (REG_BR_PROB_BASE * 3 / 8U)
-	  && prob <= (int) (REG_BR_PROB_BASE * 5 / 8U))
-	{
-	  msw_taken_prob = prob / 2U;
-	  msw_skip_prob
-	    = REG_BR_PROB_BASE * rev_prob / (REG_BR_PROB_BASE + rev_prob);
+	  && prob.initialized_p ()
+	  && prob.to_reg_br_prob_base () >= (int) (REG_BR_PROB_BASE * 3 / 8U)
+	  && prob.to_reg_br_prob_base () <= (int) (REG_BR_PROB_BASE * 5 / 8U))
+	{
+	  msw_taken_prob = prob.apply_scale (1, 2);
+	  msw_skip_prob = rev_prob.apply_scale (REG_BR_PROB_BASE,
+						rev_prob.to_reg_br_prob_base ()
+						+ REG_BR_PROB_BASE);
 	  lsw_taken_prob = prob;
 	}
       else
 	{
 	  msw_taken_prob = prob;
-	  msw_skip_prob = REG_BR_PROB_BASE;
+	  msw_skip_prob = profile_probability::guessed_always ();
 	  /* ??? If we have a constant op2h, should we use that when
 	     calculating lsw_taken_prob?  */
 	  lsw_taken_prob = prob;
diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index e19e977..733c777 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -1188,7 +1188,7 @@
    (clobber (reg:SI T_REG))]
   "can_create_pseudo_p ()"
 {
-  expand_cbranchsi4 (operands, LAST_AND_UNUSED_RTX_CODE, -1);
+  expand_cbranchsi4 (operands, LAST_AND_UNUSED_RTX_CODE);
   DONE;
 })
 
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index dae2411..f4f318a 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -7999,7 +7999,8 @@ output_cbranch (rtx op, rtx dest, int label, int reversed, int annul,
       if (*labelno && insn && (note = find_reg_note (insn, REG_BR_PROB, NULL_RTX)))
 	{
 	  strcpy (p,
-		  ((XINT (note, 0) >= REG_BR_PROB_BASE / 2) ^ far)
+		  ((profile_probability::from_reg_br_prob_note (XINT (note, 0))
+		   >= profile_probability::even ()) ^ far)
 		  ? ",pt" : ",pn");
 	  p += 3;
 	  spaces -= 3;
@@ -8462,7 +8463,8 @@ output_v9branch (rtx op, rtx dest, int reg, int label, int reversed,
   if (insn && (note = find_reg_note (insn, REG_BR_PROB, NULL_RTX)))
     {
       strcpy (p,
-	      ((XINT (note, 0) >= REG_BR_PROB_BASE / 2) ^ far)
+	      ((profile_probability::from_reg_br_prob_note (XINT (note, 0))
+	       >= profile_probability::even ()) ^ far)
 	      ? ",pt" : ",pn");
       p += 3;
     }
diff --git a/gcc/config/spu/spu.c b/gcc/config/spu/spu.c
index fcb85c0..efee614 100644
--- a/gcc/config/spu/spu.c
+++ b/gcc/config/spu/spu.c
@@ -2195,7 +2195,8 @@ get_branch_target (rtx_insn *branch)
 	    {
 	      /* If the more probable case is not a fall through, then
 	         try a branch hint.  */
-	      int prob = XINT (note, 0);
+	      int prob = profile_probability::from_reg_br_prob_note
+			    (XINT (note, 0)).to_reg_br_prob_base ();
 	      if (prob > (REG_BR_PROB_BASE * 6 / 10)
 		  && GET_CODE (XEXP (src, 1)) != PC)
 		lab = XEXP (src, 1);
@@ -4335,8 +4336,7 @@ ea_load_store_inline (rtx mem, bool is_store, rtx ea_addr, rtx data_addr)
 				      gen_rtx_IF_THEN_ELSE (VOIDmode, bcomp,
 							    hit_ref, pc_rtx)));
   /* Say that this branch is very likely to happen.  */
-  v = REG_BR_PROB_BASE - REG_BR_PROB_BASE / 100 - 1;
-  add_int_reg_note (insn, REG_BR_PROB, v);
+  add_reg_br_prob_note (insn, profile_probability::very_likely ());
 
   ea_load_store (mem, is_store, ea_addr, data_addr);
   cont_label = gen_label_rtx ();
diff --git a/gcc/config/tilegx/tilegx.c b/gcc/config/tilegx/tilegx.c
index e070e7e..dafb49d 100644
--- a/gcc/config/tilegx/tilegx.c
+++ b/gcc/config/tilegx/tilegx.c
@@ -2619,9 +2619,8 @@ cbranch_predicted_p (rtx_insn *insn)
 
   if (x)
     {
-      int pred_val = XINT (x, 0);
-
-      return pred_val >= REG_BR_PROB_BASE / 2;
+      return profile_probability::from_reg_br_prob_note (XINT (x, 0))
+	     >= profile_probability::even ();
     }
 
   return false;
diff --git a/gcc/config/tilepro/tilepro.c b/gcc/config/tilepro/tilepro.c
index 81019c1..80475b9 100644
--- a/gcc/config/tilepro/tilepro.c
+++ b/gcc/config/tilepro/tilepro.c
@@ -2419,9 +2419,8 @@ cbranch_predicted_p (rtx_insn *insn)
 
   if (x)
     {
-      int pred_val = XINT (x, 0);
-
-      return pred_val >= REG_BR_PROB_BASE / 2;
+      return profile_probability::from_reg_br_prob_note (XINT (x, 0))
+	     >= profile_probability::even ();
     }
 
   return false;