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[5/n] Handle CCMP in ifcvt to make it work with cmov

Message ID CACgzC7BmrqJ3d-aXavxHh1JJ7_ff129S-VU-EgE_GMK2LMuVRw@mail.gmail.com
State New
Headers show

Commit Message

Zhenqiang Chen March 17, 2014, 9:46 a.m. UTC
Hi,

The patch enhances ifcvt to handle conditional compare instruction
(ccmp) to make it work with cmov. For ccmp, ALLOW_CC_MODE is set to
TRUE when calling canonicalize_condition. And the backend does not
need to generate additional "compare (CC, 0)" for it.

Bootstrap and no check regression on X84-64, ARM Chromebook and qemu-aarch64.

Is it OK for next stage1?

Thanks!
-Zhenqiang

ChangeLog:
2014-03-17  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

    * ifcvt.c (struct noce_if_info): Add a new field ccmp_p.
    (noce_emit_cmove): Allow ccmp condition.
    (noce_get_alt_condition): Call canonicalize_condition with ccmp_p.
    (noce_get_condition): Set ALLOW_CC_MODE to TRUE for ccmp.
    (noce_process_if_block): Set ccmp_p for ccmp.
    * recog.h (ccmp_insn_p): New prototype.
    * recog.c (ccmp_insn_p): Make it global.
    * config/aarch64/aarch64.md (mov<mode>cc): Handle ccmp_cc.

testsuite/ChangeLog:
2014-03-17  Zhenqiang Chen  <zhenqiang.chen@linaro.org>

    * gcc.target/aarch64/ccmn-csel-1.c: New testcase.
    * gcc.target/aarch64/ccmn-csel-2.c: New testcase.
    * gcc.target/aarch64/ccmn-csel-3.c: New testcase.
    * gcc.target/aarch64/ccmp-csel-1.c: New testcase.
    * gcc.target/aarch64/ccmp-csel-2.c: New testcase.
    * gcc.target/aarch64/ccmp-csel-3.c: New testcase.
diff mbox

Patch

diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 79aa2f3..4e18bb2 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -786,6 +786,9 @@  struct noce_if_info
 
   /* Estimated cost of the particular branch instruction.  */
   int branch_cost;
+
+  /* The COND is a conditional compare.  */
+  bool ccmp_p;
 };
 
 static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
@@ -1407,9 +1410,16 @@  noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
       end_sequence ();
     }
 
-  /* Don't even try if the comparison operands are weird.  */
-  if (! general_operand (cmp_a, GET_MODE (cmp_a))
-      || ! general_operand (cmp_b, GET_MODE (cmp_b)))
+  /* Don't even try if the comparison operands are weird
+     except conditional compare.  */
+  if (if_info->ccmp_p)
+    {
+      if (!(GET_MODE_CLASS (GET_MODE (cmp_a)) == MODE_CC
+	    || GET_MODE_CLASS (GET_MODE (cmp_b)) == MODE_CC))
+	return NULL_RTX;
+    }
+  else if (! general_operand (cmp_a, GET_MODE (cmp_a))
+	   || ! general_operand (cmp_b, GET_MODE (cmp_b)))
     return NULL_RTX;
 
 #if HAVE_conditional_move
@@ -1849,7 +1859,7 @@  noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
     }
 
   cond = canonicalize_condition (if_info->jump, cond, reverse,
-				 earliest, target, false, true);
+				 earliest, target, if_info->ccmp_p, true);
   if (! cond || ! reg_mentioned_p (target, cond))
     return NULL;
 
@@ -2300,6 +2310,7 @@  noce_get_condition (rtx jump, rtx *earliest, bool then_else_reversed)
 {
   rtx cond, set, tmp;
   bool reverse;
+  int allow_cc_mode = false;
 
   if (! any_condjump_p (jump))
     return NULL_RTX;
@@ -2333,10 +2344,21 @@  noce_get_condition (rtx jump, rtx *earliest, bool then_else_reversed)
       return cond;
     }
 
+  /* For conditional compare, set ALLOW_CC_MODE to TRUE.  */
+  if (targetm.gen_ccmp_first)
+    {
+      rtx prev = prev_nonnote_nondebug_insn (jump);
+      if (prev
+	  && NONJUMP_INSN_P (prev)
+	  && BLOCK_FOR_INSN (prev) == BLOCK_FOR_INSN (jump)
+	  && ccmp_insn_p (prev))
+	allow_cc_mode = true;
+    }
+
   /* Otherwise, fall back on canonicalize_condition to do the dirty
      work of manipulating MODE_CC values and COMPARE rtx codes.  */
   tmp = canonicalize_condition (jump, cond, reverse, earliest,
-				NULL_RTX, false, true);
+				NULL_RTX, allow_cc_mode, true);
 
   /* We don't handle side-effects in the condition, like handling
      REG_INC notes and making sure no duplicate conditions are emitted.  */
@@ -2577,6 +2599,11 @@  noce_process_if_block (struct noce_if_info *if_info)
   if_info->a = a;
   if_info->b = b;
 
+  if (targetm.gen_ccmp_first)
+    if (GET_MODE_CLASS (GET_MODE (XEXP (if_info->cond, 0))) == MODE_CC
+	|| GET_MODE_CLASS (GET_MODE (XEXP (if_info->cond, 1))) == MODE_CC)
+      if_info->ccmp_p = true;
+
   /* Try optimizations in some approximation of a useful order.  */
   /* ??? Should first look to see if X is live incoming at all.  If it
      isn't, we don't need anything but an unconditional set.  */
diff -aru gcc/gcc/recog.c ccmp-all/gcc/recog.c
--- a/gcc/recog.c	2014-03-13 16:45:00.524945484 +0800
+++ b/gcc/recog.c	2014-03-13 15:30:22.468912473 +0800
@@ -556,7 +556,7 @@ 
 #define CODE_FOR_extzv	CODE_FOR_nothing
 #endif
 
-static bool
+bool
 ccmp_insn_p (rtx object)
 {
   rtx x = PATTERN (object);
diff -aru gcc/gcc/recog.h ccmp-all/gcc/recog.h
--- a/gcc/recog.h	2014-03-13 16:44:42.284945350 +0800
+++ b/gcc/recog.h	2014-03-13 15:30:22.348912472 +0800
@@ -360,5 +360,6 @@ 
 
 extern const struct insn_data_d insn_data[];
 extern int peep2_current_count;
+bool ccmp_insn_p (rtx);
 
 #endif /* GCC_RECOG_H */
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 99a6ac8..5a965f5 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -2313,15 +2359,19 @@ 
 			   (match_operand:ALLI 3 "register_operand" "")))]
   ""
   {
-    rtx ccreg;
     enum rtx_code code = GET_CODE (operands[1]);
 
     if (code == UNEQ || code == LTGT)
       FAIL;
 
-    ccreg = aarch64_gen_compare_reg (code, XEXP (operands[1], 0),
-				  XEXP (operands[1], 1));
-    operands[1] = gen_rtx_fmt_ee (code, VOIDmode, ccreg, const0_rtx);
+    if (!ccmp_cc_register (XEXP (operands[1], 0),
+			   GET_MODE (XEXP (operands[1], 0))))
+      {
+	rtx ccreg;
+	ccreg = aarch64_gen_compare_reg (code, XEXP (operands[1], 0),
+					 XEXP (operands[1], 1));
+	operands[1] = gen_rtx_fmt_ee (code, VOIDmode, ccreg, const0_rtx);
+      }
   }
 )
 
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmn-csel-1.c b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-1.c
new file mode 100644
index 0000000..330e58d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-1.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a < b && c > -5 ? d : 7;
+}
+
+/* { dg-final { scan-assembler "ccmn" } } */
+/* { dg-final { scan-assembler "csel" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmn-csel-2.c b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-2.c
new file mode 100644
index 0000000..c73d329
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-2.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a < b && c > -9 ? d : c;
+}
+
+/* { dg-final { scan-assembler "ccmn" } } */
+/* { dg-final { scan-assembler "csel" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmn-csel-3.c b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-3.c
new file mode 100644
index 0000000..64d6b0b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmn-csel-3.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a > b && c <= -2 ? 9 : 7;
+}
+
+/* { dg-final { scan-assembler "ccmn" } } */
+/* { dg-final { scan-assembler "csel" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmp-csel-1.c b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-1.c
new file mode 100644
index 0000000..ced87b5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-1.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a < b && c <= d ? d : 7;
+}
+
+/* { dg-final { scan-assembler "ccmp" } } */
+/* { dg-final { scan-assembler "csel" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmp-csel-2.c b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-2.c
new file mode 100644
index 0000000..8a4de3a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-2.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a < b && c > d ? d : c;
+}
+
+/* { dg-final { scan-assembler "ccmp" } } */
+/* { dg-final { scan-assembler "csel" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmp-csel-3.c b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-3.c
new file mode 100644
index 0000000..60b6438
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/ccmp-csel-3.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options " -O2 " } */
+
+int foo (int a, int b, int c, int d)
+{
+  return a > b && c <= d ? 9 : 7;
+}
+
+/* { dg-final { scan-assembler "ccmp" } } */
+/* { dg-final { scan-assembler "csel" } } */