[gcc r13-6148] i386: Introduce general_x64constmem_operand predicate

[gcc r13-6148] i386: Introduce general_x64constmem_operand predicate

[Uros Bizjak]

https://gcc.gnu.org/g:1eb68d9f414313da853da94fe1581256405c3e05

commit r13-6148-g1eb68d9f414313da853da94fe1581256405c3e05
Author: Uros Bizjak <ubizjak@gmail.com>
Date:   Mon Feb 20 23:17:20 2023 +0100

    i386: Introduce general_x64constmem_operand predicate
    
    Instructions that use high-part QImode registers can not be encoded
    with REX prefix.  To avoid REX prefix, operand constraints allow
    only legacy QImode registers, immediates and constant memory operands.
    The patch introduces matching predicate, so invalid operands are not
    combined into instruction RTX only to be later fixed up by reload pass.
    
    2023-02-20  Uroš Bizjak  <ubizjak@gmail.com>
    
    gcc/ChangeLog:
    
            * config/i386/predicates.md
            (general_x64constmem_operand): New predicate.
            * config/i386/i386.md (*cmpqi_ext<mode>_1):
            Use nonimm_x64constmem_operand.
            (*cmpqi_ext<mode>_3): Use general_x64constmem_operand.
            (*addqi_ext<mode>_1): Ditto.
            (*testqi_ext<mode>_1): Ditto.
            (*andqi_ext<mode>_1): Ditto.
            (*andqi_ext<mode>_1_cc): Ditto.
            (*<any_or:code>qi_ext<mode>_1): Ditto.
            (*xorqi_ext<mode>_1_cc): Ditto.

Diff:
---
 gcc/config/i386/i386.md       | 16 ++++++++--------
 gcc/config/i386/predicates.md |  7 +++++++
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 6382cfbce21..8ebb12be2c9 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -1456,7 +1456,7 @@
 (define_insn "*cmpqi_ext<mode>_1"
   [(set (reg FLAGS_REG)
 	(compare
-	  (match_operand:QI 0 "nonimmediate_operand" "QBc,m")
+	  (match_operand:QI 0 "nonimm_x64constmem_operand" "QBc,m")
 	  (subreg:QI
 	    (zero_extract:SWI248
 	      (match_operand 1 "int248_register_operand" "Q,Q")
@@ -1501,7 +1501,7 @@
 	      (match_operand 0 "int248_register_operand" "Q,Q")
 	      (const_int 8)
 	      (const_int 8)) 0)
-	  (match_operand:QI 1 "general_operand" "QnBc,m")))]
+	  (match_operand:QI 1 "general_x64constmem_operand" "QnBc,m")))]
   "ix86_match_ccmode (insn, CCmode)"
   "cmp{b}\t{%1, %h0|%h0, %1}"
   [(set_attr "isa" "*,nox64")
@@ -6683,7 +6683,7 @@
 	        (match_operand 1 "int248_register_operand" "0,0")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 2 "general_operand" "QnBc,m")) 0))
+	    (match_operand:QI 2 "general_x64constmem_operand" "QnBc,m")) 0))
    (clobber (reg:CC FLAGS_REG))]
   "/* FIXME: without this LRA can't reload this pattern, see PR82524.  */
    rtx_equal_p (operands[0], operands[1])"
@@ -9901,7 +9901,7 @@
 	        (match_operand 0 "int248_register_operand" "Q,Q")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 1 "general_operand" "QnBc,m"))
+	    (match_operand:QI 1 "general_x64constmem_operand" "QnBc,m"))
 	  (const_int 0)))]
   "ix86_match_ccmode (insn, CCNOmode)"
   "test{b}\t{%1, %h0|%h0, %1}"
@@ -10602,7 +10602,7 @@
 	        (match_operand 1 "int248_register_operand" "0,0")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 2 "general_operand" "QnBc,m")) 0))
+	    (match_operand:QI 2 "general_x64constmem_operand" "QnBc,m")) 0))
    (clobber (reg:CC FLAGS_REG))]
   "/* FIXME: without this LRA can't reload this pattern, see PR82524.  */
    rtx_equal_p (operands[0], operands[1])"
@@ -10622,7 +10622,7 @@
 	        (match_operand 1 "int248_register_operand" "0,0")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 2 "general_operand" "QnBc,m"))
+	    (match_operand:QI 2 "general_x64constmem_operand" "QnBc,m"))
 	  (const_int 0)))
    (set (zero_extract:SWI248
 	  (match_operand 0 "int248_register_operand" "+Q,Q")
@@ -11345,7 +11345,7 @@
 	        (match_operand 1 "int248_register_operand" "0,0")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 2 "general_operand" "QnBc,m")) 0))
+	    (match_operand:QI 2 "general_x64constmem_operand" "QnBc,m")) 0))
    (clobber (reg:CC FLAGS_REG))]
   "(!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun))
    /* FIXME: without this LRA can't reload this pattern, see PR82524.  */
@@ -11473,7 +11473,7 @@
 	        (match_operand 1 "int248_register_operand" "0,0")
 		(const_int 8)
 		(const_int 8)) 0)
-	    (match_operand:QI 2 "general_operand" "QnBc,m"))
+	    (match_operand:QI 2 "general_x64constmem_operand" "QnBc,m"))
 	  (const_int 0)))
    (set (zero_extract:SWI248
 	  (match_operand 0 "int248_register_operand" "+Q,Q")
diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index 7b3db0cc851..b4d9ab40ab9 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -116,6 +116,13 @@
 	    (ior (not (match_test "TARGET_64BIT"))
 		 (match_test "constant_address_p (XEXP (op, 0))")))))
 
+;; Match general operand, but exclude non-constant addresses for x86_64.
+(define_predicate "general_x64constmem_operand"
+  (ior (match_operand 0 "nonmemory_operand")
+       (and (match_operand 0 "memory_operand")
+	    (ior (not (match_test "TARGET_64BIT"))
+		 (match_test "constant_address_p (XEXP (op, 0))")))))
+
 ;; Match register operands, but include memory operands for TARGET_SSE_MATH.
 (define_predicate "register_ssemem_operand"
   (if_then_else