[PATCH] Fix RTL sharing bug (PR rtl-optimization/80903)

[PATCH] Fix RTL sharing bug (PR rtl-optimization/80903)

[Jakub Jelinek]

Hi!

As has been mentioned earlier, when the doloop code uses the expander after
expansion, we need to unshare stuff because the expander relies on unsharing
being done after it.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2017-06-02  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/80903
	* loop-doloop.c (add_test): Unshare sequence.

	* gcc.dg/pr80903.c: New test.

--- gcc/loop-doloop.c.jj	2017-03-24 14:36:35.000000000 +0100
+++ gcc/loop-doloop.c	2017-05-29 12:40:39.062107631 +0200
@@ -367,6 +367,7 @@ add_test (rtx cond, edge *e, basic_block
     }
 
   seq = get_insns ();
+  unshare_all_rtl_in_chain (seq);
   end_sequence ();
 
   /* There always is at least the jump insn in the sequence.  */
--- gcc/testsuite/gcc.dg/pr80903.c.jj	2017-05-29 12:40:27.988242239 +0200
+++ gcc/testsuite/gcc.dg/pr80903.c	2017-05-29 12:37:39.000000000 +0200
@@ -0,0 +1,34 @@
+/* PR rtl-optimization/80903 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -funroll-loops" } */
+
+short int a;
+
+void
+foo (int x, short int y, short int z)
+{
+  if (y != 0)
+    {
+      const short int b = 37;
+      y = 0;
+      while (y < b)
+	{
+	  while (y < b)
+	    {
+	    lab:
+	      ++y;
+	    }
+	  for (y = 0; y < b - 1; ++y)
+	    ;
+	  if (z != 0)
+	    {
+	      --a;
+	      y *= a;
+	    }
+	  z = x;
+	}
+      x = 0;
+    }
+
+  goto lab;
+}

	Jakub

Re: [PATCH] Fix RTL sharing bug (PR rtl-optimization/80903)

[Richard Biener]

On Fri, 2 Jun 2017, Jakub Jelinek wrote:

> Hi!
> 
> As has been mentioned earlier, when the doloop code uses the expander after
> expansion, we need to unshare stuff because the expander relies on unsharing
> being done after it.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok.

Richard.

> 2017-06-02  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR rtl-optimization/80903
> 	* loop-doloop.c (add_test): Unshare sequence.
> 
> 	* gcc.dg/pr80903.c: New test.
> 
> --- gcc/loop-doloop.c.jj	2017-03-24 14:36:35.000000000 +0100
> +++ gcc/loop-doloop.c	2017-05-29 12:40:39.062107631 +0200
> @@ -367,6 +367,7 @@ add_test (rtx cond, edge *e, basic_block
>      }
>  
>    seq = get_insns ();
> +  unshare_all_rtl_in_chain (seq);
>    end_sequence ();
>  
>    /* There always is at least the jump insn in the sequence.  */
> --- gcc/testsuite/gcc.dg/pr80903.c.jj	2017-05-29 12:40:27.988242239 +0200
> +++ gcc/testsuite/gcc.dg/pr80903.c	2017-05-29 12:37:39.000000000 +0200
> @@ -0,0 +1,34 @@
> +/* PR rtl-optimization/80903 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -funroll-loops" } */
> +
> +short int a;
> +
> +void
> +foo (int x, short int y, short int z)
> +{
> +  if (y != 0)
> +    {
> +      const short int b = 37;
> +      y = 0;
> +      while (y < b)
> +	{
> +	  while (y < b)
> +	    {
> +	    lab:
> +	      ++y;
> +	    }
> +	  for (y = 0; y < b - 1; ++y)
> +	    ;
> +	  if (z != 0)
> +	    {
> +	      --a;
> +	      y *= a;
> +	    }
> +	  z = x;
> +	}
> +      x = 0;
> +    }
> +
> +  goto lab;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)