Patchwork [AARCH64] Define REVERSIBLE_CC_MODE

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Submitter Hurugalawadi, Naveen
Date Jan. 8, 2013, 5:09 a.m.
Message ID <F3068DEED1A463459E0887A091B1549338091D@BY2PRD0710MB364.namprd07.prod.outlook.com>
Download mbox | patch
Permalink /patch/210290/
State New
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Comments

Hurugalawadi, Naveen - Jan. 8, 2013, 5:09 a.m.
Hi,

AARCH64 back-end defines REVERSE_CONDITION but not REVERSIBLE_CC_MODE.
REVERSE_CONDITION is used only in case REVERSIBLE_CC_MODE (mode) is
nonzero.

Please find attached the patch that defines REVERSIBLE_CC_MODE for 
aarch64 back-end. Please review the patch and let me know if there should be any
modifications?

Build and tested on aarch64-thunder-elf (using Cavium's internal
simulator).

Thanks,
Naveen.H.S

2013-01-08   Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>

	* config/aarch64/aarch64.h (REVERSIBLE_CC_MODE): Define.
Marcus Shawcroft - Jan. 8, 2013, 9:33 a.m.
On 8 January 2013 05:09, Hurugalawadi, Naveen
<Naveen.Hurugalawadi@caviumnetworks.com> wrote:
> Hi,
>
> AARCH64 back-end defines REVERSE_CONDITION but not REVERSIBLE_CC_MODE.
> REVERSE_CONDITION is used only in case REVERSIBLE_CC_MODE (mode) is
> nonzero.
>
> Please find attached the patch that defines REVERSIBLE_CC_MODE for
> aarch64 back-end. Please review the patch and let me know if there should be any
> modifications?
>
> Build and tested on aarch64-thunder-elf (using Cavium's internal
> simulator).
>
> Thanks,
> Naveen.H.S
>
> 2013-01-08   Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
>
>         * config/aarch64/aarch64.h (REVERSIBLE_CC_MODE): Define.


+/* A C expression whose value is one if it is always safe to reverse a
+   comparison whose mode is MODE.  If `SELECT_CC_MODE' can ever return
+   MODE for a floating-point inequality comparison, then
+   `REVERSIBLE_CC_MODE (MODE)' must be zero.
+   You need not define this macro if it would always returns zero or if the
+   floating-point format is anything other than `IEEE_FLOAT_FORMAT'.  */
+#define REVERSIBLE_CC_MODE(MODE) 1
+

Given the comment about SELECT_CC_MODE and the implementation of
aarch64_select_cc_mode this definition of REVERSIBLE_CC_MODE looks
broken to me.

/Marcus
Marcus Shawcroft - April 11, 2013, 3:21 p.m.
Naveen, I've committed your original REVERSIBLE_CC_MODE patch.

Cheers
/Marcus

On 8 January 2013 05:09, Hurugalawadi, Naveen
<Naveen.Hurugalawadi@caviumnetworks.com> wrote:
> Hi,
>
> AARCH64 back-end defines REVERSE_CONDITION but not REVERSIBLE_CC_MODE.
> REVERSE_CONDITION is used only in case REVERSIBLE_CC_MODE (mode) is
> nonzero.
>
> Please find attached the patch that defines REVERSIBLE_CC_MODE for
> aarch64 back-end. Please review the patch and let me know if there should be any
> modifications?
>
> Build and tested on aarch64-thunder-elf (using Cavium's internal
> simulator).
>
> Thanks,
> Naveen.H.S
>
> 2013-01-08   Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
>
>         * config/aarch64/aarch64.h (REVERSIBLE_CC_MODE): Define.

Patch

--- gcc/config/aarch64/aarch64.h	2013-01-08 09:42:21.081034770 +0530
+++ gcc/config/aarch64/aarch64.h	2013-01-08 09:43:52.277037865 +0530
@@ -709,6 +709,14 @@  do {									     \
 
 #define SELECT_CC_MODE(OP, X, Y)	aarch64_select_cc_mode (OP, X, Y)
 
+/* A C expression whose value is one if it is always safe to reverse a
+   comparison whose mode is MODE.  If `SELECT_CC_MODE' can ever return 
+   MODE for a floating-point inequality comparison, then 
+   `REVERSIBLE_CC_MODE (MODE)' must be zero.
+   You need not define this macro if it would always returns zero or if the
+   floating-point format is anything other than `IEEE_FLOAT_FORMAT'.  */
+#define REVERSIBLE_CC_MODE(MODE) 1
+
 #define REVERSE_CONDITION(CODE, MODE)		\
   (((MODE) == CCFPmode || (MODE) == CCFPEmode)	\
    ? reverse_condition_maybe_unordered (CODE)	\