store-merging: Allow enums during bswap recognition [PR94403]

Message ID 20200331081258.GD2212@tucnak
State New
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  • store-merging: Allow enums during bswap recognition [PR94403]
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Commit Message

Paul Hua via Gcc-patches March 31, 2020, 8:12 a.m.
Hi!

The following testcase is optimized with char/unsigned char/signed char,
but not with std::byte.  The following patch fixes that.  Didn't use
INTEGRAL_TYPE_P because bswapping bools is just too weird.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for GCC11 (or is
it simple enough that we want it in GCC10 already)?

2020-03-31  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94403
	* gimple-ssa-store-merging.c (verify_symbolic_number_p): Allow also
	ENUMERAL_TYPE lhs_type.

	* g++.dg/tree-ssa/pr94403.C: New test.


	Jakub

Comments

Richard Biener March 31, 2020, 8:53 a.m. | #1
On Tue, 31 Mar 2020, Jakub Jelinek wrote:

> Hi!

> 

> The following testcase is optimized with char/unsigned char/signed char,

> but not with std::byte.  The following patch fixes that.  Didn't use

> INTEGRAL_TYPE_P because bswapping bools is just too weird.


Is it?

> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for GCC11 (or is

> it simple enough that we want it in GCC10 already)?


OK for GCC 10.

Richard.

> 2020-03-31  Jakub Jelinek  <jakub@redhat.com>

> 

> 	PR tree-optimization/94403

> 	* gimple-ssa-store-merging.c (verify_symbolic_number_p): Allow also

> 	ENUMERAL_TYPE lhs_type.

> 

> 	* g++.dg/tree-ssa/pr94403.C: New test.

> 

> --- gcc/gimple-ssa-store-merging.c.jj	2020-03-20 09:33:03.602112329 +0100

> +++ gcc/gimple-ssa-store-merging.c	2020-03-30 18:30:31.723341519 +0200

> @@ -315,7 +315,8 @@ verify_symbolic_number_p (struct symboli

>  

>    lhs_type = gimple_expr_type (stmt);

>  

> -  if (TREE_CODE (lhs_type) != INTEGER_TYPE)

> +  if (TREE_CODE (lhs_type) != INTEGER_TYPE

> +      && TREE_CODE (lhs_type) != ENUMERAL_TYPE)

>      return false;

>  

>    if (TYPE_PRECISION (lhs_type) != TYPE_PRECISION (n->type))

> --- gcc/testsuite/g++.dg/tree-ssa/pr94403.C.jj	2020-03-30 18:42:28.563719010 +0200

> +++ gcc/testsuite/g++.dg/tree-ssa/pr94403.C	2020-03-30 18:51:21.135828389 +0200

> @@ -0,0 +1,37 @@

> +// PR tree-optimization/94403

> +// Only test on some 64-bit targets which do have bswap{si,di}2 patterns and

> +// are either big or little endian (not pdp endian).

> +// { dg-do compile { target { lp64 && { i?86-*-* x86_64-*-* powerpc*-*-* aarch64*-*-* } } } }

> +// { dg-require-effective-target store_merge }

> +// { dg-options "-O2 -fdump-tree-store-merging -std=c++17" }

> +

> +namespace std {

> +  template <typename T>

> +  void swap (T& t1, T& t2) { T tmp (t1); t1 = t2; t2 = tmp; }

> +  enum class byte : unsigned char {};

> +}

> +

> +unsigned

> +bswap32 (unsigned int x)

> +{

> +  unsigned int y = x;

> +  std::byte *bytes = reinterpret_cast<std::byte*> (&y);

> +  std::swap (bytes[0], bytes[3]);

> +  std::swap (bytes[1], bytes[2]);

> +  return y;

> +}

> +

> +unsigned long long

> +bswap64 (unsigned long long x)

> +{

> +  unsigned long long y = x;

> +  std::byte *bytes = reinterpret_cast<std::byte*> (&y);

> +  std::swap (bytes[0], bytes[7]);

> +  std::swap (bytes[1], bytes[6]);

> +  std::swap (bytes[2], bytes[5]);

> +  std::swap (bytes[3], bytes[4]);

> +  return y;

> +}

> +

> +/* { dg-final { scan-tree-dump-times "__builtin_bswap64" 1 "store-merging" } } */

> +/* { dg-final { scan-tree-dump-times "__builtin_bswap32" 1 "store-merging" } } */

> 

> 	Jakub

> 

> 


-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)

Patch

--- gcc/gimple-ssa-store-merging.c.jj	2020-03-20 09:33:03.602112329 +0100
+++ gcc/gimple-ssa-store-merging.c	2020-03-30 18:30:31.723341519 +0200
@@ -315,7 +315,8 @@  verify_symbolic_number_p (struct symboli
 
   lhs_type = gimple_expr_type (stmt);
 
-  if (TREE_CODE (lhs_type) != INTEGER_TYPE)
+  if (TREE_CODE (lhs_type) != INTEGER_TYPE
+      && TREE_CODE (lhs_type) != ENUMERAL_TYPE)
     return false;
 
   if (TYPE_PRECISION (lhs_type) != TYPE_PRECISION (n->type))
--- gcc/testsuite/g++.dg/tree-ssa/pr94403.C.jj	2020-03-30 18:42:28.563719010 +0200
+++ gcc/testsuite/g++.dg/tree-ssa/pr94403.C	2020-03-30 18:51:21.135828389 +0200
@@ -0,0 +1,37 @@ 
+// PR tree-optimization/94403
+// Only test on some 64-bit targets which do have bswap{si,di}2 patterns and
+// are either big or little endian (not pdp endian).
+// { dg-do compile { target { lp64 && { i?86-*-* x86_64-*-* powerpc*-*-* aarch64*-*-* } } } }
+// { dg-require-effective-target store_merge }
+// { dg-options "-O2 -fdump-tree-store-merging -std=c++17" }
+
+namespace std {
+  template <typename T>
+  void swap (T& t1, T& t2) { T tmp (t1); t1 = t2; t2 = tmp; }
+  enum class byte : unsigned char {};
+}
+
+unsigned
+bswap32 (unsigned int x)
+{
+  unsigned int y = x;
+  std::byte *bytes = reinterpret_cast<std::byte*> (&y);
+  std::swap (bytes[0], bytes[3]);
+  std::swap (bytes[1], bytes[2]);
+  return y;
+}
+
+unsigned long long
+bswap64 (unsigned long long x)
+{
+  unsigned long long y = x;
+  std::byte *bytes = reinterpret_cast<std::byte*> (&y);
+  std::swap (bytes[0], bytes[7]);
+  std::swap (bytes[1], bytes[6]);
+  std::swap (bytes[2], bytes[5]);
+  std::swap (bytes[3], bytes[4]);
+  return y;
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_bswap64" 1 "store-merging" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_bswap32" 1 "store-merging" } } */