[gcc r14-3671] arc: Remove obsolete mbbit-peephole option and unused patterns.

[gcc r14-3671] arc: Remove obsolete mbbit-peephole option and unused patterns.

[Claudiu Zissulescu]

https://gcc.gnu.org/g:07f7615c181dd50fdae68e37b422053554eca1ec

commit r14-3671-g07f7615c181dd50fdae68e37b422053554eca1ec
Author: Claudiu Zissulescu <claziss@gmail.com>
Date:   Tue Sep 5 11:23:26 2023 +0300

    arc: Remove obsolete mbbit-peephole option and unused patterns.
    
    gcc/
    
            * common/config/arc/arc-common.cc (arc_option_optimization_table):
            Remove mbbit_peephole.
            * config/arc/arc.md (UNSPEC_ARC_DIRECT): Remove.
            (store_direct): Likewise.
            (BBIT peephole2): Likewise.
            * config/arc/arc.opt (mbbit-peephole): Ignore option.
            * doc/invoke.texi (mbbit-peephole): Update document.
    
    Signed-off-by: Claudiu Zissulescu <claziss@gmail.com>

Diff:
---
 gcc/common/config/arc/arc-common.cc |  1 -
 gcc/config/arc/arc.md               | 31 -------------------------------
 gcc/config/arc/arc.opt              |  4 ++--
 gcc/doc/invoke.texi                 |  2 +-
 4 files changed, 3 insertions(+), 35 deletions(-)

diff --git a/gcc/common/config/arc/arc-common.cc b/gcc/common/config/arc/arc-common.cc
index 95f5dd612011..3fd66e1f6b59 100644
--- a/gcc/common/config/arc/arc-common.cc
+++ b/gcc/common/config/arc/arc-common.cc
@@ -46,7 +46,6 @@ static const struct default_options arc_option_optimization_table[] =
   {
     { OPT_LEVELS_ALL, OPT_msize_level_, NULL, 1 },
     { OPT_LEVELS_ALL, OPT_mearly_cbranchsi, NULL, 1 },
-    { OPT_LEVELS_ALL, OPT_mbbit_peephole, NULL, 1 },
     { OPT_LEVELS_SIZE, OPT_ftree_loop_optimize, NULL, 0},
     { OPT_LEVELS_SIZE, OPT_fmove_loop_invariants, NULL, 0},
     { OPT_LEVELS_SIZE, OPT_fbranch_count_reg, NULL, 0},
diff --git a/gcc/config/arc/arc.md b/gcc/config/arc/arc.md
index a4e77a207bf7..d401e600f42b 100644
--- a/gcc/config/arc/arc.md
+++ b/gcc/config/arc/arc.md
@@ -3589,37 +3589,6 @@ archs4x, archs4xd"
    (set_attr "type" "compare")
    (set_attr "length" "*,4")])
 
-; combine suffers from 'simplifications' that replace a one-bit zero
-; extract with a shift if it can prove that the upper bits are zero.
-; arc_reorg sees the code after sched2, which can have caused our
-; inputs to be clobbered even if they were not clobbered before.
-; Therefore, add a third way to convert btst / b{eq,ne} to bbit{0,1}
-; OTOH, this is somewhat marginal, and can leat to out-of-range
-; bbit (i.e. bad scheduling) and missed conditional execution,
-; so make this an option.
-(define_peephole2
-  [(set (reg:CC_ZN CC_REG)
-	(compare:CC_ZN
-	  (zero_extract:SI (match_operand:SI 0 "register_operand" "")
-			   (const_int 1)
-			   (match_operand:SI 1 "nonmemory_operand" ""))
-	  (const_int 0)))
-   (set (pc)
-	(if_then_else (match_operator 3 "equality_comparison_operator"
-				      [(reg:CC_ZN CC_REG) (const_int 0)])
-		      (label_ref (match_operand 2 "" ""))
-		      (pc)))]
-  "TARGET_BBIT_PEEPHOLE && peep2_regno_dead_p (2, CC_REG)"
-  [(parallel [(set (pc)
-		   (if_then_else
-		     (match_op_dup 3
-		       [(zero_extract:SI (match_dup 0)
-					 (const_int 1) (match_dup 1))
-			(const_int 0)])
-		     (label_ref (match_dup 2))
-		     (pc)))
-	      (clobber (reg:CC_ZN CC_REG))])])
-
 (define_insn "*cmpsi_cc_z_insn"
   [(set (reg:CC_Z CC_REG)
 	(compare:CC_Z (match_operand:SI 0 "register_operand"  "q,c")
diff --git a/gcc/config/arc/arc.opt b/gcc/config/arc/arc.opt
index 273667c9b588..4af901f26191 100644
--- a/gcc/config/arc/arc.opt
+++ b/gcc/config/arc/arc.opt
@@ -322,8 +322,8 @@ Target Var(TARGET_EARLY_CBRANCHSI)
 Enable pre-reload use of cbranchsi pattern.
 
 mbbit-peephole
-Target Var(TARGET_BBIT_PEEPHOLE)
-Enable bbit peephole2.
+Target Ignore
+Does nothing.  Preserved for backward compatibility.
 
 mcase-vector-pcrel
 Target Var(TARGET_CASE_VECTOR_PC_RELATIVE)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 435fb2fba992..33befee7d6b0 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -21603,7 +21603,7 @@ Enable the use of pre/post modify with register displacement.
 
 @opindex mbbit-peephole
 @item -mbbit-peephole
-Enable bbit peephole2.
+Does nothing.  Preserved for backward compatibility.
 
 @opindex mno-brcc
 @item -mno-brcc