arc: Remove obsolete options

Remove the following obsolete options:
- munalign-prob-threshold
- malign-call
- mmixed-code

The ARC's options are marked as obsolete and ignored for backwards
compatibility.

gcc/
2021-06-03  Claudiu Zissulescu  <claziss@synopsys.com>

	* common/config/arc/arc-common.c (arc_option_optimization_table):
	Remove malign-call.
	* config/arc/arc.c (arc_unalign_branch_p): Remove unused function.
	* config/arc/arc.h (TARGET_MIXED_CODE): Remove macro.
	(INDEX_REG_CLASS): Only refer to GENERAL_REGS.
	* config/arc/arc.md (abssi2_mixed): Remove pattern.
	* config/arc/arc.opt (munalign-prob-threshold): Mark it obsolete.
	(malign-call): Likewise.
	(mmixed-code): Likewise.
	* doc/invoke.texi (ARC): Update doc.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>

gcc/common/config/arc/arc-common.c

@@ -62,7 +62,6 @@ static const struct default_options arc_option_optimization_table[] =
     { OPT_LEVELS_SIZE, OPT_fif_conversion, NULL, 0 },
     { OPT_LEVELS_1_PLUS, OPT_fomit_frame_pointer, NULL, 1 },
     { OPT_LEVELS_3_PLUS_SPEED_ONLY, OPT_msize_level_, NULL, 0 },
-    { OPT_LEVELS_3_PLUS_SPEED_ONLY, OPT_malign_call, NULL, 1 },
     { OPT_LEVELS_NONE, 0, NULL, 0 }
   };
 

gcc/config/arc/arc.c

@@ -9868,29 +9868,6 @@ gen_acc2 (void)
   return gen_rtx_REG (SImode, TARGET_BIG_ENDIAN ? 57: 56);
 }
 
-/* FIXME: a parameter should be added, and code added to final.c,
-   to reproduce this functionality in shorten_branches.  */
-#if 0
-/* Return nonzero iff BRANCH should be unaligned if possible by upsizing
-   a previous instruction.  */
-int
-arc_unalign_branch_p (rtx branch)
-{
-  rtx note;
-
-  if (!TARGET_UNALIGN_BRANCH)
-    return 0;
-  /* Do not do this if we have a filled delay slot.  */
-  if (get_attr_delay_slot_filled (branch) == DELAY_SLOT_FILLED_YES
-      && !NEXT_INSN (branch)->deleted ())
-    return 0;
-  note = find_reg_note (branch, REG_BR_PROB, 0);
-  return (!note
-	  || (arc_unalign_prob_threshold && !br_prob_note_reliable_p (note))
-	  || INTVAL (XEXP (note, 0)) < arc_unalign_prob_threshold);
-}
-#endif
-
 /* When estimating sizes during arc_reorg, when optimizing for speed, there
    are three reasons why we need to consider branches to be length 6:
    - annull-false delay slot insns are implemented using conditional execution,

gcc/config/arc/arc.h

@@ -115,8 +115,6 @@ extern const char *arc_cpu_to_as (int argc, const char **argv);
 
 /* Run-time compilation parameters selecting different hardware subsets.  */
 
-#define TARGET_MIXED_CODE (TARGET_MIXED_CODE_SET)
-
 #define TARGET_SPFP (TARGET_SPFP_FAST_SET || TARGET_SPFP_COMPACT_SET)
 #define TARGET_DPFP (TARGET_DPFP_FAST_SET || TARGET_DPFP_COMPACT_SET	\
 		     || TARGET_FP_DP_AX)
@@ -571,7 +569,7 @@ extern enum reg_class arc_regno_reg_class[];
    a scale factor or added to another register (as well as added to a
    displacement).  */
 
-#define INDEX_REG_CLASS (TARGET_MIXED_CODE ? ARCOMPACT16_REGS : GENERAL_REGS)
+#define INDEX_REG_CLASS GENERAL_REGS
 
 /* The class value for valid base registers. A base register is one used in
    an address which is the register value plus a displacement.  */

gcc/config/arc/arc.md

@@ -2011,14 +2011,6 @@ core_3, archs4x, archs4xd, archs4xd_slow"
 
 ;; Absolute instructions
 
-(define_insn "*abssi2_mixed"
-  [(set (match_operand:SI 0 "compact_register_operand" "=q")
-	(abs:SI (match_operand:SI 1 "compact_register_operand" "q")))]
-  "TARGET_MIXED_CODE"
-  "abs%? %0,%1%&"
-  [(set_attr "type" "two_cycle_core")
-   (set_attr "iscompact" "true")])
-
 (define_insn "abssi2"
   [(set (match_operand:SI 0 "dest_reg_operand" "=Rcq#q,w,w")
 	(abs:SI (match_operand:SI 1 "nonmemory_operand" "Rcq#q,cL,Cal")))]

gcc/config/arc/arc.opt

@@ -136,12 +136,8 @@ Target Mask(CODE_DENSITY)
 Enable code density instructions for ARCv2.
 
 mmixed-code
-Target Mask(MIXED_CODE_SET)
-Tweak register allocation to help 16-bit instruction generation.
-; originally this was:
-;Generate ARCompact 16-bit instructions intermixed with 32-bit instructions
-; but we do that without -mmixed-code, too, it's just a different instruction
-; count / size tradeoff.
+Target Ignore
+Does nothing.  Preserved for backward compatibility.
 
 ; We use an explict definition for the negative form because that is the
 ; actually interesting option, and we want that to have its own comment.
@@ -292,11 +288,9 @@ mmul32x16
 Target Mask(MULMAC_32BY16_SET)
 Generate 32x16 multiply and mac instructions.
 
-; the initializer is supposed to be: Init(REG_BR_PROB_BASE/2) ,
-; alas, basic-block.h is not included in options.c .
 munalign-prob-threshold=
-Target RejectNegative Joined UInteger Var(arc_unalign_prob_threshold) Init(10000/2)
-Set probability threshold for unaligning branches.
+Target Ignore
+Does nothing.  Preserved for backward compatibility.
 
 mmedium-calls
 Target Var(TARGET_MEDIUM_CALLS) Init(TARGET_MMEDIUM_CALLS_DEFAULT)
@@ -307,8 +301,8 @@ Target Var(TARGET_ANNOTATE_ALIGN)
 Explain what alignment considerations lead to the decision to make an insn short or long.
 
 malign-call
-Target Var(TARGET_ALIGN_CALL)
-Do alignment optimizations for call instructions.
+Target Ignore
+Does nothing.  Preserved for backward compatibility.
 
 mRcq
 Target Var(TARGET_Rcq)

gcc/doc/invoke.texi

@@ -19255,7 +19255,7 @@ The following options fine tune code generation:
 @table @gcctabopt
 @item -malign-call
 @opindex malign-call
-Do alignment optimizations for call instructions.
+Does nothing.  Preserved for backward compatibility.
 
 @item -mauto-modify-reg
 @opindex mauto-modify-reg
@@ -19350,9 +19350,7 @@ code-density feature.
 
 @item -mmixed-code
 @opindex mmixed-code
-Tweak register allocation to help 16-bit instruction generation.
-This generally has the effect of decreasing the average instruction size
-while increasing the instruction count.
+Does nothing.  Preserved for backward compatibility.
 
 @item -mq-class
 @opindex mq-class
@@ -19428,12 +19426,7 @@ normal instruction.
 
 @item -munalign-prob-threshold=@var{probability}
 @opindex munalign-prob-threshold
-Set probability threshold for unaligning branches.
-When tuning for @samp{ARC700} and optimizing for speed, branches without
-filled delay slot are preferably emitted unaligned and long, unless
-profiling indicates that the probability for the branch to be taken
-is below @var{probability}.  @xref{Cross-profiling}.
-The default is (REG_BR_PROB_BASE/2), i.e.@: 5000.
+Does nothing.  Preserved for backward compatibility.
 
 @end table