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 --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 6382cfb..8ebb12b 100644 (file)
--- 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 7b3db0c..b4d9ab4 100644 (file)
--- 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