From: Uros Bizjak <ubizjak@gmail.com>
Date: Thu, 4 May 2023 18:26:12 +0000 (+0200)
Subject: i386: Tighten ashift to lea splitter operand predicates [PR109733]
X-Git-Tag: basepoints/gcc-15~9654
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8cac23781753bd8a016507dc9b21ec563e1d9b49;p=thirdparty%2Fgcc.git

i386: Tighten ashift to lea splitter operand predicates [PR109733]

The predicates of ashift to lea post-reload splitter were too broad
so the splitter tried to convert the mask shift instruction.  Tighten
operand predicates to match only general registers.

gcc/ChangeLog:

	PR target/109733
	* config/i386/predicates.md (index_reg_operand): New predicate.
	* config/i386/i386.md (ashift to lea spliter): Use
	general_reg_operand and index_reg_operand predicates.
---

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index d49f1cdc3fed..63207fc93056 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -13331,8 +13331,8 @@
 
 ;; Convert ashift to the lea pattern to avoid flags dependency.
 (define_split
-  [(set (match_operand:SWI 0 "register_operand")
-	(ashift:SWI (match_operand:SWI 1 "index_register_operand")
+  [(set (match_operand:SWI 0 "general_reg_operand")
+	(ashift:SWI (match_operand:SWI 1 "index_reg_operand")
 		    (match_operand 2 "const_0_to_3_operand")))
    (clobber (reg:CC FLAGS_REG))]
   "reload_completed
@@ -13350,9 +13350,9 @@
 
 ;; Convert ashift to the lea pattern to avoid flags dependency.
 (define_split
-  [(set (match_operand:DI 0 "register_operand")
+  [(set (match_operand:DI 0 "general_reg_operand")
 	(zero_extend:DI
-	  (ashift:SI (match_operand:SI 1 "index_register_operand")
+	  (ashift:SI (match_operand:SI 1 "index_reg_operand")
 		     (match_operand 2 "const_0_to_3_operand"))))
    (clobber (reg:CC FLAGS_REG))]
   "TARGET_64BIT && reload_completed
diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index 878b144b0fb3..362266e1f6c0 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -32,6 +32,11 @@
   (and (match_code "reg")
        (match_test "GENERAL_REGNO_P (REGNO (op))")))
 
+;; True if the operand is an INDEX class register.
+(define_predicate "index_reg_operand"
+  (and (match_code "reg")
+       (match_test "INDEX_REGNO_P (REGNO (op))")))
+
 ;; True if the operand is a nonimmediate operand with GENERAL class register.
 (define_predicate "nonimmediate_gr_operand"
   (if_then_else (match_code "reg")