Re: [PATCH] Simplify (view_convert ~a) < 0 to (view_convert a) >= 0 [PR middle-end/100738]

[Hongtao Liu <crazylht@gmail.com>]

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On Fri, Jun 4, 2021 at 1:01 PM Hongtao Liu <crazylht@gmail.com> wrote:
>
> On Tue, Jun 1, 2021 at 6:17 PM Marc Glisse <marc.glisse@inria.fr> wrote:
> >
> > On Tue, 1 Jun 2021, Hongtao Liu via Gcc-patches wrote:
> >
> > > Hi:
> > >  This patch is about to simplify (view_convert:type ~a) < 0 to
> > > (view_convert:type a) >= 0 when type is signed integer. Similar for
> > > (view_convert:type ~a) >= 0.
> > >  Bootstrapped and regtested on x86_64-linux-gnu{-m32,}.
> > >  Ok for the trunk?
> > >
> > > gcc/ChangeLog:
> > >
> > >        PR middle-end/100738
> > >        * match.pd ((view_convert ~a) < 0 --> (view_convert a) >= 0,
> > >        (view_convert ~a) >= 0 --> (view_convert a) < 0): New GIMPLE
> > >        simplification.
> >
> > We already have
> >
> > /* Fold ~X op C as X op' ~C, where op' is the swapped comparison.  */
> > (for cmp (simple_comparison)
> >       scmp (swapped_simple_comparison)
> >   (simplify
> >    (cmp (bit_not@2 @0) CONSTANT_CLASS_P@1)
> >    (if (single_use (@2)
> >         && (TREE_CODE (@1) == INTEGER_CST || TREE_CODE (@1) == VECTOR_CST))
> >     (scmp @0 (bit_not @1)))))
> >
> > Would it make sense to try and generalize it a bit, say with
> >
> > (cmp (nop_convert1? (bit_not @0)) CONSTANT_CLASS_P)
> >
> > (scmp (view_convert:XXX @0) (bit_not @1))
> >
> Thanks for your advice, it looks great.
> And can I use *view_convert1?* instead of *nop_convert1?* here,
> because the original case is view_convert, and nop_convert would fail
> to simplify the case.
Here is updated patch

gcc/ChangeLog:

        PR middle-end/100738
        * match.pd (Fold ~X op C as X op' ~C): Extend GIMPLE
        simplification to handle view_convert ~X.

gcc/testsuite/ChangeLog:

        PR middle-end/100738
        * g++.target/i386/avx2-pr100738-1.C: New test.
        * g++.target/i386/sse4_1-pr100738-1.C: New test.

> > (I still believe that it is a bad idea that SSA_NAMEs are strongly typed,
> > encoding the type in operations would be more convenient, but I think the
> > time for that choice has long gone)
> >
> > --
> > Marc Glisse
>
>
>
> --
> BR,
> Hongtao



-- 
BR,
Hongtao

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From 60308636a36fa7a5b96d115452a42be914ef19e7 Mon Sep 17 00:00:00 2001
From: liuhongt <hongtao.liu@intel.com>
Date: Thu, 27 May 2021 15:21:06 +0800
Subject: [PATCH] Extend gimple simplication of ((~X) op C --> (X) op' ~C) to
 hanlde view_convert of ~X

gcc/ChangeLog:

	PR middle-end/100738
	* match.pd (Fold ~X op C as X op' ~C): Extend GIMPLE
	simplification to handle view_convert ~X.

gcc/testsuite/ChangeLog:

	PR middle-end/100738
	* g++.target/i386/avx2-pr100738-1.C: New test.
	* g++.target/i386/sse4_1-pr100738-1.C: New test.
---
 gcc/match.pd                                  |   5 +-
 .../g++.target/i386/avx2-pr100738-1.C         | 120 ++++++++++++++++++
 .../g++.target/i386/sse4_1-pr100738-1.C       | 120 ++++++++++++++++++
 3 files changed, 243 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.target/i386/avx2-pr100738-1.C
 create mode 100644 gcc/testsuite/g++.target/i386/sse4_1-pr100738-1.C

diff --git a/gcc/match.pd b/gcc/match.pd
index cdb87636951..cbb76d67dc5 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4144,10 +4144,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for cmp (simple_comparison)
      scmp (swapped_simple_comparison)
  (simplify
-  (cmp (bit_not@2 @0) CONSTANT_CLASS_P@1)
+  (cmp (view_convert1? (bit_not@2 @0)) CONSTANT_CLASS_P@1)
+  (with {tree ttype = TREE_TYPE (@1);}
   (if (single_use (@2)
        && (TREE_CODE (@1) == INTEGER_CST || TREE_CODE (@1) == VECTOR_CST))
-   (scmp @0 (bit_not @1)))))
+   (scmp (view_convert:ttype @0) (bit_not @1))))))
 
 (for cmp (simple_comparison)
  /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
diff --git a/gcc/testsuite/g++.target/i386/avx2-pr100738-1.C b/gcc/testsuite/g++.target/i386/avx2-pr100738-1.C
new file mode 100644
index 00000000000..80fdad3e5f0
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/avx2-pr100738-1.C
@@ -0,0 +1,120 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx2 -std=c++14 -O2 -mno-avx512f -mno-xop" } */
+/* { dg-final { scan-assembler-not "pxor" } } */
+/* { dg-final { scan-assembler-not "pcmpgt\[bdq]" } } */
+/* { dg-final { scan-assembler-times "pblendvb" 6 } } */
+/* { dg-final { scan-assembler-times "blendvps" 6 } } */
+/* { dg-final { scan-assembler-times "blendvpd" 6 } } */
+
+typedef char v32qi __attribute__ ((vector_size (32)));
+typedef short v16hi __attribute__ ((vector_size (32)));
+typedef int v8si __attribute__ ((vector_size (32)));
+typedef long long v4di __attribute__ ((vector_size (32)));
+
+v8si
+f1 (v32qi a, v8si b, v8si c)
+{
+  return ((v8si)~a) < 0 ? b : c;
+}
+
+v4di
+f2 (v32qi a, v4di b, v4di c)
+{
+  return ((v4di)~a) < 0 ? b : c;
+}
+
+v32qi
+f3 (v16hi a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) < 0 ? b : c;
+}
+
+v8si
+f4 (v16hi a, v8si b, v8si c)
+{
+  return ((v8si)~a) < 0 ? b : c;
+}
+
+v4di
+f5 (v16hi a, v4di b, v4di c)
+{
+  return ((v4di)~a) < 0 ? b : c;
+}
+
+v32qi
+f6 (v8si a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) < 0 ? b : c;
+}
+
+v4di
+f7 (v8si a, v4di b, v4di c)
+{
+  return ((v4di)~a) < 0 ? b : c;
+}
+
+v32qi
+f8 (v4di a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) < 0 ? b : c;
+}
+
+v8si
+f9 (v4di a, v8si b, v8si c)
+{
+  return ((v8si)~a) < 0 ? b : c;
+}
+
+v8si
+f10 (v32qi a, v8si b, v8si c)
+{
+  return ((v8si)~a) >= 0 ? b : c;
+}
+
+v4di
+f11 (v32qi a, v4di b, v4di c)
+{
+  return ((v4di)~a) >= 0 ? b : c;
+}
+
+v32qi
+f12 (v16hi a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) >= 0 ? b : c;
+}
+
+v8si
+f13 (v16hi a, v8si b, v8si c)
+{
+  return ((v8si)~a) >= 0 ? b : c;
+}
+
+v4di
+f14 (v16hi a, v4di b, v4di c)
+{
+  return ((v4di)~a) >= 0 ? b : c;
+}
+
+v32qi
+f15 (v8si a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) >= 0 ? b : c;
+}
+
+v4di
+f16 (v8si a, v4di b, v4di c)
+{
+  return ((v4di)~a) >= 0 ? b : c;
+}
+
+v32qi
+f17 (v4di a, v32qi b, v32qi c)
+{
+  return ((v32qi)~a) >= 0 ? b : c;
+}
+
+v8si
+f18 (v4di a, v8si b, v8si c)
+{
+  return ((v8si)~a) >= 0 ? b : c;
+}
diff --git a/gcc/testsuite/g++.target/i386/sse4_1-pr100738-1.C b/gcc/testsuite/g++.target/i386/sse4_1-pr100738-1.C
new file mode 100644
index 00000000000..d3454c264cd
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/sse4_1-pr100738-1.C
@@ -0,0 +1,120 @@
+/* { dg-do compile } */
+/* { dg-options "-msse4 -std=c++14 -mno-avx2 -O2 -mno-xop" } */
+/* { dg-final { scan-assembler-not "pxor" } } */
+/* { dg-final { scan-assembler-not "pcmpgt\[bdq]" } } */
+/* { dg-final { scan-assembler-times "pblendvb" 6 } } */
+/* { dg-final { scan-assembler-times "blendvps" 6 } } */
+/* { dg-final { scan-assembler-times "blendvpd" 6 } } */
+
+typedef char v16qi __attribute__ ((vector_size (16)));
+typedef short v8hi __attribute__ ((vector_size (16)));
+typedef int v4si __attribute__ ((vector_size (16)));
+typedef long long v2di __attribute__ ((vector_size (16)));
+
+v4si
+f1 (v16qi a, v4si b, v4si c)
+{
+  return ((v4si)~a) < 0 ? b : c;
+}
+
+v2di
+f2 (v16qi a, v2di b, v2di c)
+{
+  return ((v2di)~a) < 0 ? b : c;
+}
+
+v16qi
+f3 (v8hi a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) < 0 ? b : c;
+}
+
+v4si
+f4 (v8hi a, v4si b, v4si c)
+{
+  return ((v4si)~a) < 0 ? b : c;
+}
+
+v2di
+f5 (v8hi a, v2di b, v2di c)
+{
+  return ((v2di)~a) < 0 ? b : c;
+}
+
+v16qi
+f6 (v4si a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) < 0 ? b : c;
+}
+
+v2di
+f7 (v4si a, v2di b, v2di c)
+{
+  return ((v2di)~a) < 0 ? b : c;
+}
+
+v16qi
+f8 (v2di a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) < 0 ? b : c;
+}
+
+v4si
+f9 (v2di a, v4si b, v4si c)
+{
+  return ((v4si)~a) < 0 ? b : c;
+}
+
+v4si
+f10 (v16qi a, v4si b, v4si c)
+{
+  return ((v4si)~a) >= 0 ? b : c;
+}
+
+v2di
+f11 (v16qi a, v2di b, v2di c)
+{
+  return ((v2di)~a) >= 0 ? b : c;
+}
+
+v16qi
+f12 (v8hi a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) >= 0 ? b : c;
+}
+
+v4si
+f13 (v8hi a, v4si b, v4si c)
+{
+  return ((v4si)~a) >= 0 ? b : c;
+}
+
+v2di
+f14 (v8hi a, v2di b, v2di c)
+{
+  return ((v2di)~a) >= 0 ? b : c;
+}
+
+v16qi
+f15 (v4si a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) >= 0 ? b : c;
+}
+
+v2di
+f16 (v4si a, v2di b, v2di c)
+{
+  return ((v2di)~a) >= 0 ? b : c;
+}
+
+v16qi
+f17 (v2di a, v16qi b, v16qi c)
+{
+  return ((v16qi)~a) >= 0 ? b : c;
+}
+
+v4si
+f18 (v2di a, v4si b, v4si c)
+{
+  return ((v4si)~a) >= 0 ? b : c;
+}
-- 
2.18.1