[AArch64] Use conditional negate for abs

2015-05-14  Wilco Dijkstra  <wdijkstr@arm.com>

      gcc/
	* config/aarch64/aarch64.md (absdi2): Optimize abs expansion.
	(csneg3<mode>_insn): Enable expansion of pattern.

      gcc/testsuite/
	* gcc.target/aarch64/abs_1.c (abs64): Update test for new abs expansion.
	(abs64_in_dreg): Likewise.

From-SVN: r223197

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1b78ca32e5fbf9126b379cf1ea6295fbcf72161f..ba35c777c7f2251bc4ebe7427698a586de92d6c0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-05-14  Wilco Dijkstra  <wdijkstr@arm.com>
+
+       * config/aarch64/aarch64.md (absdi2): Optimize abs expansion.
+       (csneg3<mode>_insn): Enable expansion of pattern.
+
 2015-05-14  Nick Clifton  <nickc@redhat.com>
 
        * config/rl78/rl78.c (rl78_select_section): Select the correct

diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 1dbadc0c5a45e809033b2570c498984873e75240..4817fae5d32268a8666544c48ec135375c8c2236 100644 (file)
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -2182,34 +2182,16 @@
   [(set_attr "type" "alu_ext")]
 )
 
-(define_insn_and_split "absdi2"
-  [(set (match_operand:DI 0 "register_operand" "=&r,w")
-       (abs:DI (match_operand:DI 1 "register_operand" "r,w")))]
+(define_expand "abs<mode>2"
+  [(match_operand:GPI 0 "register_operand" "")
+   (match_operand:GPI 1 "register_operand" "")]
   ""
-  "@
-   #
-   abs\\t%d0, %d1"
-  "reload_completed
-   && GP_REGNUM_P (REGNO (operands[0]))
-   && GP_REGNUM_P (REGNO (operands[1]))"
-  [(const_int 0)]
   {
-    emit_insn (gen_rtx_SET (operands[0],
-                           gen_rtx_XOR (DImode,
-                                        gen_rtx_ASHIFTRT (DImode,
-                                                          operands[1],
-                                                          GEN_INT (63)),
-                                        operands[1])));
-    emit_insn (gen_rtx_SET (operands[0],
-                           gen_rtx_MINUS (DImode,
-                                          operands[0],
-                                          gen_rtx_ASHIFTRT (DImode,
-                                                            operands[1],
-                                                            GEN_INT (63)))));
+    rtx ccreg = aarch64_gen_compare_reg (LT, operands[1], const0_rtx);
+    rtx x = gen_rtx_LT (VOIDmode, ccreg, const0_rtx);
+    emit_insn (gen_csneg3<mode>_insn (operands[0], x, operands[1], operands[1]));
     DONE;
   }
-  [(set_attr "type" "alu_sreg")
-   (set_attr "simd" "no,yes")]
 )
 
 (define_insn "neg<mode>2"
@@ -2888,7 +2870,7 @@
   [(set_attr "type" "csel")]
 )
 
-(define_insn "*csneg3<mode>_insn"
+(define_insn "csneg3<mode>_insn"
   [(set (match_operand:GPI 0 "register_operand" "=r")
         (if_then_else:GPI
          (match_operand 1 "aarch64_comparison_operation" "")

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ef46d503bf5ad972223605aa7d7b0f5024101071..504dc075ef18dfde3327fe73b711b73909e137c9 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-05-14  Wilco Dijkstra  <wdijkstr@arm.com>
+
+       * gcc.target/aarch64/abs_1.c (abs64): Update test for new abs expansion.
+       (abs64_in_dreg): Likewise.
+
 2015-05-14  Marek Polacek  <polacek@redhat.com>
 
        PR c/66066

diff --git a/gcc/testsuite/gcc.target/aarch64/abs_1.c b/gcc/testsuite/gcc.target/aarch64/abs_1.c
index 938bc84ed9599e550e3e8207f371dbb57e7efca3..11f1095199c7156ad0e071177bab7804e16b5074 100644 (file)
--- a/gcc/testsuite/gcc.target/aarch64/abs_1.c
+++ b/gcc/testsuite/gcc.target/aarch64/abs_1.c
@@ -7,15 +7,14 @@ extern void abort (void);
 long long
 abs64 (long long a)
 {
-  /* { dg-final { scan-assembler "eor\t" } } */
-  /* { dg-final { scan-assembler "sub\t" } } */
+  /* { dg-final { scan-assembler "csneg\t" } } */
   return llabs (a);
 }
 
 long long
 abs64_in_dreg (long long a)
 {
-  /* { dg-final { scan-assembler "abs\td\[0-9\]+, d\[0-9\]+" } } */
+  /* { dg-final { scan-assembler "csneg\t" } } */
   register long long x asm ("d8") = a;
   register long long y asm ("d9");
   asm volatile ("" : : "w" (x));