On Fri, Oct 31, 2014 at 8:53 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Fri, Oct 31, 2014 at 08:45:54PM +0100, Uros Bizjak wrote:
>> Attached patch works around PR 63620. Patched gcc will allow only a
>> subset of CONST_DOUBLEs in FP push patterns. This subset will result
>> in direct immediates that can always be encoded directly in the insn
>> stream. These won't be reloaded through memory, and will avoid PIC
>> register re-materialization issues. OTOH, the patch will generate
>> non-optimal push sequences when general registers are available.
>>
>> 2014-10-31 Uros Bizjak <ubiz...@gmail.com>
>>
>> PR target/63620
>> * config/i386/i386.md (*pushtf): Allow only CONST_DOUBLES that won't
>> be reloaded through memory.
>> (*pushxf): Ditto.
>> (*pushdf): Ditto.
>>
>> The patch was bootstrapped and regression tested on x86_64-linux-gnu
>> {-m32}. The patch was also checked with Darwin crosscompiler on the
>> testcases in the PR.
>
> Can't you limit the workaround to ix86_use_pseudo_pic_reg () only
> if it is about PIC register changes?
Indeed, thanks for the suggestion.
I will amend the patch with the attached.
Thanks,
Uros.
Index: i386-protos.h
===================================================================
--- i386-protos.h (revision 216987)
+++ i386-protos.h (working copy)
@@ -42,6 +42,8 @@
extern void ix86_reset_previous_fndecl (void);
+extern bool ix86_use_pseudo_pic_reg (void);
+
#ifdef RTX_CODE
extern int standard_80387_constant_p (rtx);
extern const char *standard_80387_constant_opcode (rtx);
Index: i386.c
===================================================================
--- i386.c (revision 216987)
+++ i386.c (working copy)
@@ -6158,7 +6158,7 @@
/* Return 1 if pseudo register should be created and used to hold
GOT address for PIC code. */
-static bool
+bool
ix86_use_pseudo_pic_reg (void)
{
if ((TARGET_64BIT
Index: i386.md
===================================================================
--- i386.md (revision 216987)
+++ i386.md (working copy)
@@ -2738,7 +2738,8 @@
[(set (match_operand:TF 0 "push_operand" "=<,<")
(match_operand:TF 1 "general_no_elim_operand" "x,*roF"))]
"(TARGET_64BIT || TARGET_SSE)
- && (!can_create_pseudo_p ()
+ && (!ix86_use_pseudo_pic_reg ()
+ || !can_create_pseudo_p ()
|| GET_CODE (operands[1]) != CONST_DOUBLE
|| standard_sse_constant_p (operands[1]))"
{
@@ -2766,7 +2767,8 @@
(define_insn "*pushxf"
[(set (match_operand:XF 0 "push_operand" "=<,<")
(match_operand:XF 1 "general_no_elim_operand" "f,Yx*roF"))]
- "!can_create_pseudo_p ()
+ "!ix86_use_pseudo_pic_reg ()
+ || !can_create_pseudo_p ()
|| GET_CODE (operands[1]) != CONST_DOUBLE
|| standard_80387_constant_p (operands[1]) > 0"
{
@@ -2800,7 +2802,8 @@
(define_insn "*pushdf"
[(set (match_operand:DF 0 "push_operand" "=<,<,<,<")
(match_operand:DF 1 "general_no_elim_operand" "f,Yd*roF,rmF,x"))]
- "!can_create_pseudo_p ()
+ "!ix86_use_pseudo_pic_reg ()
+ || !can_create_pseudo_p ()
|| GET_CODE (operands[1]) != CONST_DOUBLE
|| (!(TARGET_SSE2 && TARGET_SSE_MATH)
&& standard_80387_constant_p (operands[1]) > 0)
