Thanks for the advice, updated patch in attachment.
Bootstrapped/regtested on x86-64-pc-linux-gnu. Ok for trunk?
Uros Bizjak <ubiz...@gmail.com> 于2024年6月12日周三 18:12写道：
>
> On Wed, Jun 12, 2024 at 12:00 PM Uros Bizjak <ubiz...@gmail.com> wrote:
> >
> > On Wed, Jun 12, 2024 at 5:12 AM Hongyu Wang <hongyu.w...@intel.com> wrote:
> > >
> > > 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}";
> > > + }
> >
> > This could be implemented as an alternative using "r,C" constraint as
> > the first constraint for operands[2,3]. Then the register allocator
> > will match the constraints for you.
>
> Like in the attached (lightly tested) patch.
>
> Uros.
From e03199bcbbd12b296c1da7cf3200896df0e15536 Mon Sep 17 00:00:00 2001
From: Hongyu Wang <hongyu.w...@intel.com>
Date: Thu, 9 May 2024 10:12:16 +0800
Subject: [PATCH] [APX CCMP] Use ctestcc when comparing to const 0
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.
gcc/ChangeLog:
* config/i386/i386.md (@ccmp<mode>): Add new alternative
<r>,C and adjust output templates. Also adjust UNSPEC mode
to CCmode.
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 | 11 +++++++----
gcc/testsuite/gcc.target/i386/apx-ccmp-1.c | 10 ++++++----
gcc/testsuite/gcc.target/i386/apx-ccmp-2.c | 4 ++--
3 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index a64f2ad4f5f..48deb3b9bdd 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -1515,14 +1515,17 @@ (define_insn "@ccmp<mode>"
(match_operator 1 "comparison_operator"
[(reg:CC FLAGS_REG) (const_int 0)])
(compare:CC
- (minus:SWI (match_operand:SWI 2 "nonimmediate_operand" "<r>m,<r>")
- (match_operand:SWI 3 "<general_operand>" "<r><i>,<r><m>"))
+ (minus:SWI (match_operand:SWI 2 "nonimmediate_operand" "<r>,<r>m,<r>")
+ (match_operand:SWI 3 "<general_operand>" "C,<r><i>,<r><m>"))
(const_int 0))
- (unspec:SI
+ (unspec:CC
[(match_operand:SI 4 "const_0_to_15_operand")]
UNSPEC_APX_DFV)))]
"TARGET_APX_CCMP"
- "ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}"
+ "@
+ ctest%C1{<imodesuffix>}\t%G4 %2, %2
+ ccmp%C1{<imodesuffix>}\t%G4 {%3, %2|%2, %3}
+ 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
