[PATCH] [APX CCMP] Use ctestcc when comparing to const 0

[Hongyu Wang]

Hi,

For CTEST, we don't have conditional AND so there's no optimization
opportunity to write a new ctest pattern. Emit ctest when ccmp did
comparison to const 0 to save bytes.

Bootstrapped & regtested under x86-64-pc-linux-gnu.

Ok for trunk?

gcc/ChangeLog:

        * config/i386/i386.md (@ccmp<mode>): Use ctestcc when
        operands[3] is const0_rtx.

gcc/testsuite/ChangeLog:

        * gcc.target/i386/apx-ccmp-1.c: Adjust output to scan ctest.
        * gcc.target/i386/apx-ccmp-2.c: Adjust some condition to
        compare with 0.
---
 gcc/config/i386/i386.md                    |  6 +++++-
 gcc/testsuite/gcc.target/i386/apx-ccmp-1.c | 10 ++++++----
 gcc/testsuite/gcc.target/i386/apx-ccmp-2.c |  4 ++--
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index a64f2ad4f5f..014d48cddd6 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -1522,7 +1522,11 @@ (define_insn "@ccmp<mode>"
          [(match_operand:SI 4 "const_0_to_15_operand")]
          UNSPEC_APX_DFV)))]
  "TARGET_APX_CCMP"
- "ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}"
+ {
+   if (operands[3] == const0_rtx && !MEM_P (operands[2]))
+     return "ctest%C1{<imodesuffix>}\t%G4 %2, %2";
+   return "ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}";
+ }
  [(set_attr "type" "icmp")
   (set_attr "mode" "<MODE>")
   (set_attr "length_immediate" "1")
diff --git a/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c 
b/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
index e4e112f07e0..a8b70576760 100644
--- a/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
+++ b/gcc/testsuite/gcc.target/i386/apx-ccmp-1.c
@@ -96,9 +96,11 @@ f15 (double a, double b, int c, int d)
 
 /* { dg-final { scan-assembler-times "ccmpg" 2 } } */
 /* { dg-final { scan-assembler-times "ccmple" 2 } } */
-/* { dg-final { scan-assembler-times "ccmpne" 4 } } */
-/* { dg-final { scan-assembler-times "ccmpe" 3 } } */
+/* { dg-final { scan-assembler-times "ccmpne" 2 } } */
+/* { dg-final { scan-assembler-times "ccmpe" 1 } } */
 /* { dg-final { scan-assembler-times "ccmpbe" 1 } } */
+/* { dg-final { scan-assembler-times "ctestne" 2 } } */
+/* { dg-final { scan-assembler-times "cteste" 2 } } */
 /* { dg-final { scan-assembler-times "ccmpa" 1 } } */
-/* { dg-final { scan-assembler-times "ccmpbl" 2 } } */
-
+/* { dg-final { scan-assembler-times "ccmpbl" 1 } } */
+/* { dg-final { scan-assembler-times "ctestbl" 1 } } */
diff --git a/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c 
b/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
index 0123a686d2c..4a0784394c3 100644
--- a/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
+++ b/gcc/testsuite/gcc.target/i386/apx-ccmp-2.c
@@ -12,7 +12,7 @@ int foo_apx(int a, int b, int c, int d)
       c += d;
       a += b;
       sum += a + c;
-      if (b != d && sum < c || sum > d)
+      if (b > d && sum != 0 || sum > d)
        {
          b += d;
          sum += b;
@@ -32,7 +32,7 @@ int foo_noapx(int a, int b, int c, int d)
       c += d;
       a += b;
       sum += a + c;
-      if (b != d && sum < c || sum > d)
+      if (b > d && sum != 0 || sum > d)
        {
          b += d;
          sum += b;
-- 
2.31.1