diff mbox series

[rs6000] Update powerpc vector load builtins with PURE attribute

Message ID 23b90519d01bf01af4bdbe6dcae72b08019d8b6f.camel@vnet.ibm.com
State New
Headers show
Series [rs6000] Update powerpc vector load builtins with PURE attribute | expand

Commit Message

will schmidt Sept. 26, 2019, 3:40 p.m. UTC 
Hi,
    
Update our (rs6000) vector load built-ins with the PURE attribute.  These
were previously given the MEM attribute, which meant that redundant loads
surrounding the built-in calls could not be eliminated in earlier passes
since they were defined as having the potential to touch memory.
    
This change has been tested across assorted powerpc
systems (p7, p8le, p8be, p9) with no regressions noted.
    
OK for trunk?
    
Thanks,
-Will
    
[gcc]
    
2019-09-26  Will Schmidt <will_schmidt@vnet.ibm.com>
    	* config/rs6000/rs6000-builtin.def: ( LVSL LVSR LVEBX LVEHX
    	LVEWX LVXL LVXL_V2DF LVXL_V2DI LVXL_V4SF LVXL_V4SI LVXL_V8HI
    	LVXL_V16QI LVX LVX_V1TI LVX_V2DF LVX_V2DI LVX_V4SF LVX_V4SI
    	LVX_V8HI LVX_V16QI LVLX LVLXL LVRX LVRXL LXSDX LXVD2X_V1TI
    	LXVD2X_V2DF LXVD2X_V2DI LXVDSX LXVW4X_V4SF LXVW4X_V4SI
    	LXVW4X_V8HI LXVW4X_V16QI LD_ELEMREV_V1TI LD_ELEMREV_V2DF
    	LD_ELEMREV_V2DI LD_ELEMREV_V4SF LD_ELEMREV_V4SI LD_ELEMREV_V8HI
    	LD_ELEMREV_V16QI): Use the PURE attribute.
    
[testsuite]
    
2019-09-26  Will Schmidt <will_schmidt@vnet.ibm.com>
    	* gcc.target/powerpc/pure-builtin-redundant-load.c:  New.

Comments

Segher Boessenkool Sept. 26, 2019, 5 p.m. UTC | #1 
Hi Will,

On Thu, Sep 26, 2019 at 10:40:29AM -0500, will schmidt wrote:
> Update our (rs6000) vector load built-ins with the PURE attribute.  These
> were previously given the MEM attribute, which meant that redundant loads
> surrounding the built-in calls could not be eliminated in earlier passes
> since they were defined as having the potential to touch memory.

> 2019-09-26  Will Schmidt <will_schmidt@vnet.ibm.com>
>     	* config/rs6000/rs6000-builtin.def: ( LVSL LVSR LVEBX LVEHX
                                             ^--- stray space

Please put commas between the items, too?

The patch is okay for trunk.  Thank you!


Segher
Bill Schmidt Sept. 26, 2019, 5:06 p.m. UTC | #2 
On 9/26/19 12:00 PM, Segher Boessenkool wrote:
> Hi Will,
>
> On Thu, Sep 26, 2019 at 10:40:29AM -0500, will schmidt wrote:
>> Update our (rs6000) vector load built-ins with the PURE attribute.  These
>> were previously given the MEM attribute, which meant that redundant loads
>> surrounding the built-in calls could not be eliminated in earlier passes
>> since they were defined as having the potential to touch memory.
>> 2019-09-26  Will Schmidt <will_schmidt@vnet.ibm.com>
>>      	* config/rs6000/rs6000-builtin.def: ( LVSL LVSR LVEBX LVEHX
>                                               ^--- stray space
>
> Please put commas between the items, too?
>
> The patch is okay for trunk.  Thank you!
>
I wonder whether we should also consider a backport to 9, when we 
started expanding these earlier.  Thoughts?

Bill

> Segher
Segher Boessenkool Sept. 26, 2019, 5:11 p.m. UTC | #3 
On Thu, Sep 26, 2019 at 12:06:03PM -0500, Bill Schmidt wrote:
> On 9/26/19 12:00 PM, Segher Boessenkool wrote:
> >On Thu, Sep 26, 2019 at 10:40:29AM -0500, will schmidt wrote:
> >>Update our (rs6000) vector load built-ins with the PURE attribute.  These
> >>were previously given the MEM attribute, which meant that redundant loads
> >>surrounding the built-in calls could not be eliminated in earlier passes
> >>since they were defined as having the potential to touch memory.
> >>2019-09-26  Will Schmidt <will_schmidt@vnet.ibm.com>
> >>     	* config/rs6000/rs6000-builtin.def: ( LVSL LVSR LVEBX LVEHX
> >                                              ^--- stray space
> >
> >Please put commas between the items, too?
> >
> >The patch is okay for trunk.  Thank you!
> >
> I wonder whether we should also consider a backport to 9, when we 
> started expanding these earlier.  Thoughts?

Good idea, yeah.  After waiting for a week or so to see if problems turn
up on trunk, as usual.


Segher
diff mbox series

Patch

diff --git a/gcc/config/rs6000/rs6000-builtin.def b/gcc/config/rs6000/rs6000-builtin.def
index 0a2bdb7..4d4f3b3 100644
--- a/gcc/config/rs6000/rs6000-builtin.def
+++ b/gcc/config/rs6000/rs6000-builtin.def
@@ -1175,41 +1175,41 @@  BU_ALTIVEC_P (VCMPGTUB_P,     "vcmpgtub_p",	CONST,	vector_gtu_v16qi_p)
 /* AltiVec builtins that are handled as special cases.  */
 BU_ALTIVEC_X (MTVSCR,		"mtvscr",	    MISC)
 BU_ALTIVEC_X (MFVSCR,		"mfvscr",	    MISC)
 BU_ALTIVEC_X (DSSALL,		"dssall",	    MISC)
 BU_ALTIVEC_X (DSS,		"dss",		    MISC)
-BU_ALTIVEC_X (LVSL,		"lvsl",		    MEM)
-BU_ALTIVEC_X (LVSR,		"lvsr",		    MEM)
-BU_ALTIVEC_X (LVEBX,		"lvebx",	    MEM)
-BU_ALTIVEC_X (LVEHX,		"lvehx",	    MEM)
-BU_ALTIVEC_X (LVEWX,		"lvewx",	    MEM)
-BU_ALTIVEC_X (LVXL,		"lvxl",		    MEM)
-BU_ALTIVEC_X (LVXL_V2DF,	"lvxl_v2df",	    MEM)
-BU_ALTIVEC_X (LVXL_V2DI,	"lvxl_v2di",	    MEM)
-BU_ALTIVEC_X (LVXL_V4SF,	"lvxl_v4sf",	    MEM)
-BU_ALTIVEC_X (LVXL_V4SI,	"lvxl_v4si",	    MEM)
-BU_ALTIVEC_X (LVXL_V8HI,	"lvxl_v8hi",	    MEM)
-BU_ALTIVEC_X (LVXL_V16QI,	"lvxl_v16qi",	    MEM)
-BU_ALTIVEC_X (LVX,		"lvx",		    MEM)
-BU_ALTIVEC_X (LVX_V1TI,		"lvx_v1ti",	    MEM)
-BU_ALTIVEC_X (LVX_V2DF,		"lvx_v2df",	    MEM)
-BU_ALTIVEC_X (LVX_V2DI,		"lvx_v2di",	    MEM)
-BU_ALTIVEC_X (LVX_V4SF,		"lvx_v4sf",	    MEM)
-BU_ALTIVEC_X (LVX_V4SI,		"lvx_v4si",	    MEM)
-BU_ALTIVEC_X (LVX_V8HI,		"lvx_v8hi",	    MEM)
-BU_ALTIVEC_X (LVX_V16QI,	"lvx_v16qi",	    MEM)
+BU_ALTIVEC_X (LVSL,		"lvsl",		    PURE)
+BU_ALTIVEC_X (LVSR,		"lvsr",		    PURE)
+BU_ALTIVEC_X (LVEBX,		"lvebx",	    PURE)
+BU_ALTIVEC_X (LVEHX,		"lvehx",	    PURE)
+BU_ALTIVEC_X (LVEWX,		"lvewx",	    PURE)
+BU_ALTIVEC_X (LVXL,		"lvxl",		    PURE)
+BU_ALTIVEC_X (LVXL_V2DF,	"lvxl_v2df",	    PURE)
+BU_ALTIVEC_X (LVXL_V2DI,	"lvxl_v2di",	    PURE)
+BU_ALTIVEC_X (LVXL_V4SF,	"lvxl_v4sf",	    PURE)
+BU_ALTIVEC_X (LVXL_V4SI,	"lvxl_v4si",	    PURE)
+BU_ALTIVEC_X (LVXL_V8HI,	"lvxl_v8hi",	    PURE)
+BU_ALTIVEC_X (LVXL_V16QI,	"lvxl_v16qi",	    PURE)
+BU_ALTIVEC_X (LVX,		"lvx",		    PURE)
+BU_ALTIVEC_X (LVX_V1TI,		"lvx_v1ti",	    PURE)
+BU_ALTIVEC_X (LVX_V2DF,		"lvx_v2df",	    PURE)
+BU_ALTIVEC_X (LVX_V2DI,		"lvx_v2di",	    PURE)
+BU_ALTIVEC_X (LVX_V4SF,		"lvx_v4sf",	    PURE)
+BU_ALTIVEC_X (LVX_V4SI,		"lvx_v4si",	    PURE)
+BU_ALTIVEC_X (LVX_V8HI,		"lvx_v8hi",	    PURE)
+BU_ALTIVEC_X (LVX_V16QI,	"lvx_v16qi",	    PURE)
 BU_ALTIVEC_X (STVX,		"stvx",		    MEM)
 BU_ALTIVEC_X (STVX_V2DF,	"stvx_v2df",	    MEM)
 BU_ALTIVEC_X (STVX_V2DI,	"stvx_v2di",	    MEM)
 BU_ALTIVEC_X (STVX_V4SF,	"stvx_v4sf",	    MEM)
 BU_ALTIVEC_X (STVX_V4SI,	"stvx_v4si",	    MEM)
 BU_ALTIVEC_X (STVX_V8HI,	"stvx_v8hi",	    MEM)
 BU_ALTIVEC_X (STVX_V16QI,	"stvx_v16qi",	    MEM)
-BU_ALTIVEC_C (LVLX,		"lvlx",		    MEM)
-BU_ALTIVEC_C (LVLXL,		"lvlxl",	    MEM)
-BU_ALTIVEC_C (LVRX,		"lvrx",		    MEM)
-BU_ALTIVEC_C (LVRXL,		"lvrxl",	    MEM)
+BU_ALTIVEC_C (LVLX,		"lvlx",		    PURE)
+BU_ALTIVEC_C (LVLXL,		"lvlxl",	    PURE)
+BU_ALTIVEC_C (LVRX,		"lvrx",		    PURE)
+BU_ALTIVEC_C (LVRXL,		"lvrxl",	    PURE)
 BU_ALTIVEC_X (STVEBX,		"stvebx",	    MEM)
 BU_ALTIVEC_X (STVEHX,		"stvehx",	    MEM)
 BU_ALTIVEC_X (STVEWX,		"stvewx",	    MEM)
 BU_ALTIVEC_X (STVXL,		"stvxl",	    MEM)
 BU_ALTIVEC_X (STVXL_V2DF,	"stvxl_v2df",	    MEM)
@@ -1716,34 +1716,34 @@  BU_VSX_P (XVCMPGTSP_P,	      "xvcmpgtsp_p",	CONST,	vector_gt_v4sf_p)
 BU_VSX_P (XVCMPEQDP_P,	      "xvcmpeqdp_p",	CONST,	vector_eq_v2df_p)
 BU_VSX_P (XVCMPGEDP_P,	      "xvcmpgedp_p",	CONST,	vector_ge_v2df_p)
 BU_VSX_P (XVCMPGTDP_P,	      "xvcmpgtdp_p",	CONST,	vector_gt_v2df_p)
 
 /* VSX builtins that are handled as special cases.  */
-BU_VSX_X (LXSDX,	      "lxsdx",		MEM)
-BU_VSX_X (LXVD2X_V1TI,	      "lxvd2x_v1ti",	MEM)
-BU_VSX_X (LXVD2X_V2DF,	      "lxvd2x_v2df",	MEM)
-BU_VSX_X (LXVD2X_V2DI,	      "lxvd2x_v2di",	MEM)
-BU_VSX_X (LXVDSX,	      "lxvdsx",		MEM)
-BU_VSX_X (LXVW4X_V4SF,	      "lxvw4x_v4sf",	MEM)
-BU_VSX_X (LXVW4X_V4SI,        "lxvw4x_v4si",	MEM)
-BU_VSX_X (LXVW4X_V8HI,        "lxvw4x_v8hi",	MEM)
-BU_VSX_X (LXVW4X_V16QI,	      "lxvw4x_v16qi",	MEM)
+BU_VSX_X (LXSDX,	      "lxsdx",		PURE)
+BU_VSX_X (LXVD2X_V1TI,	      "lxvd2x_v1ti",	PURE)
+BU_VSX_X (LXVD2X_V2DF,	      "lxvd2x_v2df",	PURE)
+BU_VSX_X (LXVD2X_V2DI,	      "lxvd2x_v2di",	PURE)
+BU_VSX_X (LXVDSX,	      "lxvdsx",		PURE)
+BU_VSX_X (LXVW4X_V4SF,	      "lxvw4x_v4sf",	PURE)
+BU_VSX_X (LXVW4X_V4SI,	      "lxvw4x_v4si",	PURE)
+BU_VSX_X (LXVW4X_V8HI,	      "lxvw4x_v8hi",	PURE)
+BU_VSX_X (LXVW4X_V16QI,	      "lxvw4x_v16qi",	PURE)
 BU_VSX_X (STXSDX,	      "stxsdx",		MEM)
 BU_VSX_X (STXVD2X_V1TI,	      "stxvd2x_v1ti",	MEM)
 BU_VSX_X (STXVD2X_V2DF,	      "stxvd2x_v2df",	MEM)
 BU_VSX_X (STXVD2X_V2DI,	      "stxvd2x_v2di",	MEM)
 BU_VSX_X (STXVW4X_V4SF,	      "stxvw4x_v4sf",	MEM)
 BU_VSX_X (STXVW4X_V4SI,	      "stxvw4x_v4si",	MEM)
 BU_VSX_X (STXVW4X_V8HI,	      "stxvw4x_v8hi",	MEM)
 BU_VSX_X (STXVW4X_V16QI,      "stxvw4x_v16qi",	MEM)
-BU_VSX_X (LD_ELEMREV_V1TI,    "ld_elemrev_v1ti",  MEM)
-BU_VSX_X (LD_ELEMREV_V2DF,    "ld_elemrev_v2df",  MEM)
-BU_VSX_X (LD_ELEMREV_V2DI,    "ld_elemrev_v2di",  MEM)
-BU_VSX_X (LD_ELEMREV_V4SF,    "ld_elemrev_v4sf",  MEM)
-BU_VSX_X (LD_ELEMREV_V4SI,    "ld_elemrev_v4si",  MEM)
-BU_VSX_X (LD_ELEMREV_V8HI,    "ld_elemrev_v8hi",  MEM)
-BU_VSX_X (LD_ELEMREV_V16QI,   "ld_elemrev_v16qi", MEM)
+BU_VSX_X (LD_ELEMREV_V1TI,    "ld_elemrev_v1ti",  PURE)
+BU_VSX_X (LD_ELEMREV_V2DF,    "ld_elemrev_v2df",  PURE)
+BU_VSX_X (LD_ELEMREV_V2DI,    "ld_elemrev_v2di",  PURE)
+BU_VSX_X (LD_ELEMREV_V4SF,    "ld_elemrev_v4sf",  PURE)
+BU_VSX_X (LD_ELEMREV_V4SI,    "ld_elemrev_v4si",  PURE)
+BU_VSX_X (LD_ELEMREV_V8HI,    "ld_elemrev_v8hi",  PURE)
+BU_VSX_X (LD_ELEMREV_V16QI,   "ld_elemrev_v16qi", PURE)
 BU_VSX_X (ST_ELEMREV_V1TI,    "st_elemrev_v1ti",  MEM)
 BU_VSX_X (ST_ELEMREV_V2DF,    "st_elemrev_v2df",  MEM)
 BU_VSX_X (ST_ELEMREV_V2DI,    "st_elemrev_v2di",  MEM)
 BU_VSX_X (ST_ELEMREV_V4SF,    "st_elemrev_v4sf",  MEM)
 BU_VSX_X (ST_ELEMREV_V4SI,    "st_elemrev_v4si",  MEM)
diff --git a/gcc/testsuite/gcc.target/powerpc/pure-builtin-redundant-load.c b/gcc/testsuite/gcc.target/powerpc/pure-builtin-redundant-load.c
new file mode 100644
index 0000000..16ab6ab
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pure-builtin-redundant-load.c
@@ -0,0 +1,47 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_vsx_ok } */
+/* { dg-options "-O2 -fdump-tree-fre-all -mvsx" } */
+
+/* Verify we remove a redundant load that occurs both before and after
+we call a vector load builtin.
+This testcase is introduced as we updated a number of our vector load
+built-ins with the attribute of PURE instead of MEM, to indicate that
+those builtins only read from memory, versus reading from and writing
+to the same.
+This means we can identify the redundant load instructions in an earlier
+pass, and optimize them away.  */
+
+#include <altivec.h>
+
+vector signed short load_data;
+
+vector signed short foo()
+{
+	vector signed short r11,r12,r13;
+	r11 = load_data;
+	r12 = vec_xl (0, &load_data[0]);
+	r13 = load_data;
+	return (r11 + r12 + r13);
+}
+
+vector signed short biz()
+{
+	vector signed short r21,r22,r23;
+	r21 = load_data;
+	r22 = vec_lvehx (0, &load_data[0]);
+	r23 = load_data;
+	return (r21 + r22 + r23);
+}
+
+vector signed short bar()
+{
+	vector signed short r31,r32,r33;
+	r31 = load_data;
+	r32 = vec_lvx (0, &load_data[0]);
+	r33 = load_data;
+	return (r31 + r32 + r33);
+}
+
+/* { dg-final { scan-tree-dump-times "Removing dead stmt r13_. = load_data;" 1 "fre1" } } */
+/* { dg-final { scan-tree-dump-times "Removing dead stmt r23_. = load_data;" 1 "fre1" } } */
+/* { dg-final { scan-tree-dump-times "Removing dead stmt r33_. = load_data;" 1 "fre1" } } */