[Patch][google/gcc-4_8] Backport r198101 (fix for PR56847) into google/gcc-4_8

[沈涵]

Hi, this patch back port trunk@198101 to fix PR rtl-optimization/56847.

Passed bootstrap and regression test.

Ok for branch google/gcc-4_8?

2013-04-19  Vladimir Makarov  

PR rtl-optimization/56847
* lra-constraints.c (process_alt_operands): Discourage alternative
with non-matche doffsettable memory constraint fro memory with
known offset.

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index e3b4add..9e4924c 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -1978,8 +1978,15 @@ process_alt_operands (int only_alternative)
   (op, this_alternative) == NO_REGS
  reject += LRA_MAX_REJECT;

-  if (! ((const_to_mem && constmemok)
- || (MEM_P (op) && offmemok)))
+  if (MEM_P (op) && offmemok)
+ {
+  /* If we know offset and this non-offsetable memory,
+ something wrong with this memory and it is better
+ to try other memory possibilities.  */
+  if (MEM_OFFSET_KNOWN_P (op))
+reject += LRA_MAX_REJECT;
+ }
+  else if (! (const_to_mem && constmemok))
  {
   /* We prefer to reload pseudos over reloading other
  things, since such reloads may be able to be
diff --git a/gcc/testsuite/gcc.dg/pr56847.c b/gcc/testsuite/gcc.dg/pr56847.c
new file mode 100644
index 000..b94aae1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr56847.c
@@ -0,0 +1,12 @@
+/* PR rtl-optimization/56847 */
+/* { dg-do compile { target pie } } */
+/* { dg-options "-O2 -fpie" } */
+
+struct S { long int a, b; } e;
+__thread struct S s;
+
+void
+foo (void)
+{
+  s = e;
+}


H.

Re: [Patch][google/gcc-4_8] Backport r198101 (fix for PR56847) into google/gcc-4_8

[Dehao Chen]

Looks good.

Dehao

On Wed, Apr 24, 2013 at 5:49 PM, Han Shen(沈涵)  wrote:
> Hi, this patch back port trunk@198101 to fix PR rtl-optimization/56847.
>
> Passed bootstrap and regression test.
>
> Ok for branch google/gcc-4_8?
>
> 2013-04-19  Vladimir Makarov  
>
> PR rtl-optimization/56847
> * lra-constraints.c (process_alt_operands): Discourage alternative
> with non-matche doffsettable memory constraint fro memory with
> known offset.
>
> diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
> index e3b4add..9e4924c 100644
> --- a/gcc/lra-constraints.c
> +++ b/gcc/lra-constraints.c
> @@ -1978,8 +1978,15 @@ process_alt_operands (int only_alternative)
>(op, this_alternative) == NO_REGS
>   reject += LRA_MAX_REJECT;
>
> -  if (! ((const_to_mem && constmemok)
> - || (MEM_P (op) && offmemok)))
> +  if (MEM_P (op) && offmemok)
> + {
> +  /* If we know offset and this non-offsetable memory,
> + something wrong with this memory and it is better
> + to try other memory possibilities.  */
> +  if (MEM_OFFSET_KNOWN_P (op))
> +reject += LRA_MAX_REJECT;
> + }
> +  else if (! (const_to_mem && constmemok))
>   {
>/* We prefer to reload pseudos over reloading other
>   things, since such reloads may be able to be
> diff --git a/gcc/testsuite/gcc.dg/pr56847.c b/gcc/testsuite/gcc.dg/pr56847.c
> new file mode 100644
> index 000..b94aae1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr56847.c
> @@ -0,0 +1,12 @@
> +/* PR rtl-optimization/56847 */
> +/* { dg-do compile { target pie } } */
> +/* { dg-options "-O2 -fpie" } */
> +
> +struct S { long int a, b; } e;
> +__thread struct S s;
> +
> +void
> +foo (void)
> +{
> +  s = e;
> +}
>
>
> H.