[Patch 1/4] Simplify the representation of CCMP patterns by using

    2015-01-19  Wilco Dijkstra  <wdijkstr@arm.com>

    gcc/
        * target.def (gen_ccmp_first): Update documentation.
        (gen_ccmp_next): Likewise.
        * doc/tm.texi (gen_ccmp_first): Update documentation.
        (gen_ccmp_next): Likewise.
        * ccmp.c (expand_ccmp_expr): Extract cmp_code from return value of
        expand_ccmp_expr_1.  Improve comments.
        * config/aarch64/aarch64.md (ccmp_and): Use if_then_else for ccmp.
        (ccmp_ior<mode>): Remove pattern.
        (cmp<mode>): Remove expand.
        (cmp): Globalize pattern.
        (cstorecc4): Use cc_register.
        (mov<mode>cc): Remove ccmp_cc_register check.
        * config/aarch64/aarch64.c (aarch64_get_condition_code_1):
        Simplify after removal of CC_DNE/* modes.
        (aarch64_ccmp_mode_to_code): Remove.
        (aarch64_print_operand): Remove 'K' case.  Merge 'm' and 'M' cases.
        In 'k' case use integer as condition.
        (aarch64_nzcv_codes): Remove inverted cases.
        (aarch64_code_to_ccmode): Remove.
        (aarch64_gen_ccmp_first): Use cmp pattern directly.  Return the correct
        comparison with CC register to be used in folowing CCMP/branch/CSEL.
        (aarch64_gen_ccmp_next): Use previous comparison and mode in CCMP
        pattern.  Return the comparison with CC register.  Invert conditions
        when bitcode is OR.
        * config/aarch64/aarch64-modes.def: Remove CC_DNE/* modes.
        * config/aarch64/predicates.md (ccmp_cc_register): Remove.

From-SVN: r232561

1 files changed, 14 insertions, 7 deletions

diff --git a/gcc/ccmp.c b/gcc/ccmp.c
index 72f2db1d62e..28fe189c67f 100644
--- a/gcc/ccmp.c
+++ b/gcc/ccmp.c
@@ -49,6 +49,10 @@ along with GCC; see the file COPYING3.  If not see
 	 - gen_ccmp_first expands the first compare in CCMP.
 	 - gen_ccmp_next expands the following compares.
 
+       Both hooks return a comparison with the CC register that is equivalent
+       to the value of the gimple comparison.  This is used by the next CCMP
+       and in the final conditional store.
+
      * We use cstorecc4 pattern to convert the CCmode intermediate to
        the integer mode result that expand_normal is expecting.
 
@@ -114,10 +118,12 @@ ccmp_candidate_p (gimple *g)
   return false;
 }
 
-/* PREV is the CC flag from precvious compares.  The function expands the
-   next compare based on G which ops previous compare with CODE.
+/* PREV is a comparison with the CC register which represents the
+   result of the previous CMP or CCMP.  The function expands the
+   next compare based on G which is ANDed/ORed with the previous
+   compare depending on CODE.
    PREP_SEQ returns all insns to prepare opearands for compare.
-   GEN_SEQ returnss all compare insns.  */
+   GEN_SEQ returns all compare insns.  */
 static rtx
 expand_ccmp_next (gimple *g, enum tree_code code, rtx prev,
 		  rtx *prep_seq, rtx *gen_seq)
@@ -210,7 +216,7 @@ expand_ccmp_expr_1 (gimple *g, rtx *prep_seq, rtx *gen_seq)
   return NULL_RTX;
 }
 
-/* Main entry to expand conditional compare statement G. 
+/* Main entry to expand conditional compare statement G.
    Return NULL_RTX if G is not a legal candidate or expand fail.
    Otherwise return the target.  */
 rtx
@@ -233,9 +239,10 @@ expand_ccmp_expr (gimple *g)
       enum insn_code icode;
       enum machine_mode cc_mode = CCmode;
       tree lhs = gimple_assign_lhs (g);
+      rtx_code cmp_code = GET_CODE (tmp);
 
 #ifdef SELECT_CC_MODE
-      cc_mode = SELECT_CC_MODE (NE, tmp, const0_rtx);
+      cc_mode = SELECT_CC_MODE (cmp_code, XEXP (tmp, 0), const0_rtx);
 #endif
       icode = optab_handler (cstore_optab, cc_mode);
       if (icode != CODE_FOR_nothing)
@@ -246,8 +253,8 @@ expand_ccmp_expr (gimple *g)
 	  emit_insn (prep_seq);
 	  emit_insn (gen_seq);
 
-	  tmp = emit_cstore (target, icode, NE, cc_mode, cc_mode,
-			     0, tmp, const0_rtx, 1, mode);
+	  tmp = emit_cstore (target, icode, cmp_code, cc_mode, cc_mode,
+			     0, XEXP (tmp, 0), const0_rtx, 1, mode);
 	  if (tmp)
 	    return tmp;
 	}