From 3f0d6479205271cac38387aac65cc1a02a3f84a4 Mon Sep 17 00:00:00 2001
From: Michael Beck <beck@ipd.info.uni-karlsruhe.de>
Date: Wed, 16 Aug 2006 13:31:41 +0000
Subject: [PATCH 1/1] Added osr_flag_ignore_x86_shift flag that ignores
 multiplications by 2, 4, 8

[r8127]
---
 ir/opt/opt_osr.c | 20 ++++++++++++++++++--
 ir/opt/opt_osr.h |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/ir/opt/opt_osr.c b/ir/opt/opt_osr.c
index 6a54ad2b2..3d2094317 100644
--- a/ir/opt/opt_osr.c
+++ b/ir/opt/opt_osr.c
@@ -290,7 +290,7 @@ static ir_node *do_apply(opcode code, dbg_info *db, ir_node *op1, ir_node *op2,
  *               the opcode, debug-info and mode of a newly created one
  * @param op1    the first operand
  * @param op2    the second operand
- * @param env     the environment
+ * @param env    the environment
  *
  * @return the newly created node
  */
@@ -443,8 +443,24 @@ static int check_replace(ir_node *irn, iv_env *env) {
 			iv = right; rc = left;
 		}
 
-		if (iv)
+		if (iv) {
+			if (env->flags & osr_flag_ignore_x86_shift) {
+				if (is_Const(rc)) {
+					tarval *tv = get_Const_tarval(rc);
+
+					if (tarval_is_long(tv)) {
+						long value = get_tarval_long(tv);
+
+						if (value == 2 || value == 4 || value == 8) {
+							/* do not reduce multiplications by 2, 4, 8 */
+							break;
+						}
+					}
+				}
+			}
+
 			return replace(irn, iv, rc, env);
+		}
 		break;
 	default:
 		break;
diff --git a/ir/opt/opt_osr.h b/ir/opt/opt_osr.h
index 24548587c..464caabba 100644
--- a/ir/opt/opt_osr.h
+++ b/ir/opt/opt_osr.h
@@ -20,6 +20,7 @@ typedef enum osr_flags {
 	osr_flag_none               = 0,  /**< no additional flags */
 	osr_flag_lftr_with_ov_check = 1,  /**< do linear function test replacement
 	                                       only if no overflow can occur. */
+	osr_flag_ignore_x86_shift   = 2   /**< ignore Multiplications by 2, 4, 8 */
 } osr_flags;
 
 /* FirmJNI cannot handle identical enum values... */
-- 
2.20.1