From: Michael Meissner <meissner@linux.ibm.com>
To: Michael Meissner <meissner@linux.ibm.com>,
gcc-patches@gcc.gnu.org,
Segher Boessenkool <segher@kernel.crashing.org>,
"Kewen.Lin" <linkw@linux.ibm.com>,
David Edelsohn <dje.gcc@gmail.com>,
Peter Bergner <bergner@linux.ibm.com>,
Will Schmidt <will_schmidt@vnet.ibm.com>
Subject: [PATCH 8/8] Add saturating subtract built-ins.
Date: Fri, 3 Feb 2023 16:37:08 -0500 [thread overview]
Message-ID: <Y91+hDeMysjK0B4Y@toto.the-meissners.org> (raw)
In-Reply-To: <Y915kdrgaQxmJl9A@toto.the-meissners.org>
This patch adds support for a saturating subtract built-in function that may be
added to a future PowerPC processor. Note, if it is added, the name of the
built-in function may change before GCC 13 is released. If the name changes,
we will submit a patch changing the name.
I also added support for providing dense math built-in functions, even though
at present, we have not added any new built-in functions for dense math. It is
likely we will want to add new dense math built-in functions as the dense math
support is fleshed out.
I tested this patch on a little endian power10 system with long double using
the tradiational IBM double double format. Assuming the other 6 patches for
-mcpu=future are checked in (or at least the first patch), can I check this
patch into the master branch for GCC 13.
Note, I will be on vacation from Tuesday February 7th through Tuesday February
14th.
2023-02-03 Michael Meissner <meissner@linux.ibm.com>
gcc/
* config/rs6000/rs6000-builtin.cc (rs6000_invalid_builtin): Add support
for flagging invalid use of future built-in functions.
(rs6000_builtin_is_supported): Add support for future built-in
functions.
* config/rs6000/rs6000-builtins.def (__builtin_saturate_subtract32): New
built-in function for -mcpu=future.
(__builtin_saturate_subtract64): Likewise.
* config/rs6000/rs6000-gen-builtins.cc (enum bif_stanza): Add stanzas
for -mcpu=future built-ins.
(stanza_map): Likewise.
(enable_string): Likewise.
(struct attrinfo): Likewise.
(parse_bif_attrs): Likewise.
(write_decls): Likewise.
* config/rs6000/rs6000.md (sat_sub<mode>3): Add saturating subtract
built-in insn declarations.
(sat_sub<mode>3_dot): Likewise.
(sat_sub<mode>3_dot2): Likewise.
* doc/extend.texi (Future PowerPC built-ins): New section.
gcc/testsuite/
* gcc.target/powerpc/subfus-1.c: New test.
* gcc.target/powerpc/subfus-2.c: Likewise.
---
gcc/config/rs6000/rs6000-builtin.cc | 17 ++++++
gcc/config/rs6000/rs6000-builtins.def | 11 ++++
gcc/config/rs6000/rs6000-gen-builtins.cc | 35 ++++++++++--
gcc/config/rs6000/rs6000.md | 60 +++++++++++++++++++++
gcc/doc/extend.texi | 24 +++++++++
gcc/testsuite/gcc.target/powerpc/subfus-1.c | 32 +++++++++++
gcc/testsuite/gcc.target/powerpc/subfus-2.c | 32 +++++++++++
gcc/testsuite/lib/target-supports.exp | 16 +++++-
8 files changed, 220 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/subfus-1.c
create mode 100644 gcc/testsuite/gcc.target/powerpc/subfus-2.c
diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc
index d971cf90e51..b9b0b2d52d0 100644
--- a/gcc/config/rs6000/rs6000-builtin.cc
+++ b/gcc/config/rs6000/rs6000-builtin.cc
@@ -139,6 +139,17 @@ rs6000_invalid_builtin (enum rs6000_gen_builtins fncode)
case ENB_MMA:
error ("%qs requires the %qs option", name, "-mmma");
break;
+ case ENB_FUTURE:
+ error ("%qs requires the %qs option", name, "-mcpu=future");
+ break;
+ case ENB_FUTURE_64:
+ error ("%qs requires the %qs option and either the %qs or %qs option",
+ name, "-mcpu=future", "-m64", "-mpowerpc64");
+ break;
+ case ENB_DM:
+ error ("%qs requires the %qs or %qs options", name, "-mcpu=future",
+ "-mdense-math");
+ break;
default:
case ENB_ALWAYS:
gcc_unreachable ();
@@ -194,6 +205,12 @@ rs6000_builtin_is_supported (enum rs6000_gen_builtins fncode)
return TARGET_HTM;
case ENB_MMA:
return TARGET_MMA;
+ case ENB_FUTURE:
+ return TARGET_FUTURE;
+ case ENB_FUTURE_64:
+ return TARGET_FUTURE && TARGET_POWERPC64;
+ case ENB_DM:
+ return TARGET_DENSE_MATH;
default:
gcc_unreachable ();
}
diff --git a/gcc/config/rs6000/rs6000-builtins.def b/gcc/config/rs6000/rs6000-builtins.def
index e0d9f5adc97..8b73e994558 100644
--- a/gcc/config/rs6000/rs6000-builtins.def
+++ b/gcc/config/rs6000/rs6000-builtins.def
@@ -139,6 +139,8 @@
; endian Needs special handling for endianness
; ibmld Restrict usage to the case when TFmode is IBM-128
; ibm128 Restrict usage to the case where __ibm128 is supported or if ibmld
+; future Restrict usage to future instructions
+; dm Restrict usage to dense math
;
; Each attribute corresponds to extra processing required when
; the built-in is expanded. All such special processing should
@@ -4108,3 +4110,12 @@
void __builtin_vsx_stxvp (v256, unsigned long, const v256 *);
STXVP nothing {mma,pair}
+
+[future]
+ const signed int __builtin_saturate_subtract32 (signed int, signed int);
+ SAT_SUBSI sat_subsi3 {}
+
+[future-64]
+ const signed long __builtin_saturate_subtract64 (signed long, signed long);
+ SAT_SUBDI sat_subdi3 {}
+
diff --git a/gcc/config/rs6000/rs6000-gen-builtins.cc b/gcc/config/rs6000/rs6000-gen-builtins.cc
index a2f442ed90d..daf7fff079e 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.cc
+++ b/gcc/config/rs6000/rs6000-gen-builtins.cc
@@ -233,6 +233,9 @@ enum bif_stanza
BSTZ_P10,
BSTZ_P10_64,
BSTZ_MMA,
+ BSTZ_FUTURE,
+ BSTZ_FUTURE_64,
+ BSTZ_DM,
NUMBIFSTANZAS
};
@@ -266,7 +269,10 @@ static stanza_entry stanza_map[NUMBIFSTANZAS] =
{ "htm", BSTZ_HTM },
{ "power10", BSTZ_P10 },
{ "power10-64", BSTZ_P10_64 },
- { "mma", BSTZ_MMA }
+ { "mma", BSTZ_MMA },
+ { "future", BSTZ_FUTURE },
+ { "future-64", BSTZ_FUTURE_64 },
+ { "dm", BSTZ_DM },
};
static const char *enable_string[NUMBIFSTANZAS] =
@@ -291,7 +297,10 @@ static const char *enable_string[NUMBIFSTANZAS] =
"ENB_HTM",
"ENB_P10",
"ENB_P10_64",
- "ENB_MMA"
+ "ENB_MMA",
+ "ENB_FUTURE",
+ "ENB_FUTURE_64",
+ "ENB_DM",
};
/* Function modifiers provide special handling for const, pure, and fpmath
@@ -395,6 +404,8 @@ struct attrinfo
bool isendian;
bool isibmld;
bool isibm128;
+ bool isfuture;
+ bool isdm;
};
/* Fields associated with a function prototype (bif or overload). */
@@ -1477,7 +1488,8 @@ parse_bif_attrs (attrinfo *attrptr)
"ldvec = %d, stvec = %d, reve = %d, pred = %d, htm = %d, "
"htmspr = %d, htmcr = %d, mma = %d, quad = %d, pair = %d, "
"mmaint = %d, no32bit = %d, 32bit = %d, cpu = %d, ldstmask = %d, "
- "lxvrse = %d, lxvrze = %d, endian = %d, ibmdld = %d, ibm128 = %d.\n",
+ "lxvrse = %d, lxvrze = %d, endian = %d, ibmdld = %d, ibm128 = %d,",
+ "future = %d, dm = %d.\n",
attrptr->isinit, attrptr->isset, attrptr->isextract,
attrptr->isnosoft, attrptr->isldvec, attrptr->isstvec,
attrptr->isreve, attrptr->ispred, attrptr->ishtm, attrptr->ishtmspr,
@@ -1485,7 +1497,7 @@ parse_bif_attrs (attrinfo *attrptr)
attrptr->ismmaint, attrptr->isno32bit, attrptr->is32bit,
attrptr->iscpu, attrptr->isldstmask, attrptr->islxvrse,
attrptr->islxvrze, attrptr->isendian, attrptr->isibmld,
- attrptr->isibm128);
+ attrptr->isibm128, attrptr->isfuture, attrptr->isdm);
#endif
return PC_OK;
@@ -2257,7 +2269,10 @@ write_decls (void)
fprintf (header_file, " ENB_HTM,\n");
fprintf (header_file, " ENB_P10,\n");
fprintf (header_file, " ENB_P10_64,\n");
- fprintf (header_file, " ENB_MMA\n");
+ fprintf (header_file, " ENB_MMA,\n");
+ fprintf (header_file, " ENB_FUTURE,\n");
+ fprintf (header_file, " ENB_FUTURE_64,\n");
+ fprintf (header_file, " ENB_DM\n");
fprintf (header_file, "};\n\n");
fprintf (header_file, "#define PPC_MAXRESTROPNDS 3\n");
@@ -2301,6 +2316,8 @@ write_decls (void)
fprintf (header_file, "#define bif_endian_bit\t\t(0x00200000)\n");
fprintf (header_file, "#define bif_ibmld_bit\t\t(0x00400000)\n");
fprintf (header_file, "#define bif_ibm128_bit\t\t(0x00800000)\n");
+ fprintf (header_file, "#define bif_future_bit\t\t(0x01000000)\n");
+ fprintf (header_file, "#define bif_dm_bit\t\t(0x02000000)\n");
fprintf (header_file, "\n");
fprintf (header_file,
"#define bif_is_init(x)\t\t((x).bifattrs & bif_init_bit)\n");
@@ -2350,6 +2367,10 @@ write_decls (void)
"#define bif_is_ibmld(x)\t((x).bifattrs & bif_ibmld_bit)\n");
fprintf (header_file,
"#define bif_is_ibm128(x)\t((x).bifattrs & bif_ibm128_bit)\n");
+ fprintf (header_file,
+ "#define bif_is_future(x)\t((x).bifattrs & bif_future_bit)\n");
+ fprintf (header_file,
+ "#define bif_is_dm(x)\t((x).bifattrs & bif_dm_bit)\n");
fprintf (header_file, "\n");
fprintf (header_file,
@@ -2548,6 +2569,10 @@ write_bif_static_init (void)
fprintf (init_file, " | bif_ibmld_bit");
if (bifp->attrs.isibm128)
fprintf (init_file, " | bif_ibm128_bit");
+ if (bifp->attrs.isfuture)
+ fprintf (init_file, " | bif_future_bit");
+ if (bifp->attrs.isdm)
+ fprintf (init_file, " | bif_dm_bit");
fprintf (init_file, ",\n");
fprintf (init_file, " /* restr_opnd */\t{%d, %d, %d},\n",
bifp->proto.restr_opnd[0], bifp->proto.restr_opnd[1],
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index ee7651d9b43..f9e231c16be 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -15654,6 +15654,66 @@ (define_insn "hashchk"
}
[(set_attr "type" "load")])
\f
+;; Signed saturation.
+
+;; The subfus instruction is defined as: SUBFUS RT,L,RA,RB. The extended
+;; mnemonic that we use (subdus and subwus) has the arguments RA and RB
+;; reversed (so it becomes a subtract instead of subtract from).
+
+(define_insn "sat_sub<mode>3"
+ [(set (match_operand:GPR 0 "gpc_reg_operand" "=r")
+ (ss_minus:GPR (match_operand:GPR 1 "gpc_reg_operand" "r")
+ (match_operand:GPR 2 "gpc_reg_operand" "r")))]
+ "TARGET_FUTURE"
+ "sub<wd>us %0,%1,%2"
+ [(set_attr "type" "add")])
+
+(define_insn_and_split "*sat_sub<mode>3_dot"
+ [(set (match_operand:CC 3 "cc_reg_operand" "=x,?y")
+ (compare:CC (ss_minus:GPR (match_operand:GPR 1 "gpc_reg_operand" "r,r")
+ (match_operand:GPR 2 "gpc_reg_operand" "r,r"))
+ (const_int 0)))
+ (clobber (match_scratch:GPR 0 "=r,r"))]
+ "TARGET_FUTURE"
+ "@
+ sub<wd>us. %0,%1,%2
+ #"
+ "&& reload_completed && cc_reg_not_cr0_operand (operands[3], CCmode)"
+ [(set (match_dup 0)
+ (ss_minus:GPR (match_dup 1)
+ (match_dup 2)))
+ (set (match_dup 3)
+ (compare:CC (match_dup 0)
+ (const_int 0)))]
+ ""
+ [(set_attr "type" "add")
+ (set_attr "dot" "yes")
+ (set_attr "length" "4,8")])
+
+(define_insn_and_split "*sat_sub<mode>3_dot2"
+ [(set (match_operand:CC 3 "cc_reg_operand" "=x,?y")
+ (compare:CC (ss_minus:GPR (match_operand:GPR 1 "gpc_reg_operand" "r,r")
+ (match_operand:GPR 2 "gpc_reg_operand" "r,r"))
+ (const_int 0)))
+ (set (match_operand:GPR 0 "gpc_reg_operand" "=r,r")
+ (ss_minus:GPR (match_dup 1)
+ (match_dup 2)))]
+ "TARGET_FUTURE"
+ "@
+ sub<wd>us. %0,%1,%2
+ #"
+ "&& reload_completed && cc_reg_not_cr0_operand (operands[3], CCmode)"
+ [(set (match_dup 0)
+ (ss_minus:GPR (match_dup 1)
+ (match_dup 2)))
+ (set (match_dup 3)
+ (compare:CC (match_dup 0)
+ (const_int 0)))]
+ ""
+ [(set_attr "type" "add")
+ (set_attr "dot" "yes")
+ (set_attr "length" "4,8")])
+\f
(include "sync.md")
(include "vector.md")
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 5a026c4b48c..a6d25b5b618 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -17839,6 +17839,7 @@ Disable global interrupt.
* Basic PowerPC Built-in Functions Available on ISA 2.07::
* Basic PowerPC Built-in Functions Available on ISA 3.0::
* Basic PowerPC Built-in Functions Available on ISA 3.1::
+* Basic Built-in Functions that may be available on future PowerPCs::
@end menu
This section describes PowerPC built-in functions that do not require
@@ -18496,6 +18497,29 @@ ISA 3.1 @code{stxvrbx}, @code{stxvrhx}, @code{stxvrwx}, and @code{stxvrdx}
instructions.
@findex vec_xst_trunc
+@node Basic Built-in Functions that may be available on future PowerPCs
+@subsubsection Potential future PowerPC Built-in Functions
+
+The built-in functions described in this section may be available on
+future PowerPC processors. At present, these built-ins exist to
+allowing testing of new instructions. There is no guarantee that
+these instructions will actually be implemented.
+
+The following built-in functions are available on Linux 64-bit systems
+that use a potential future instruction set (@option{-mcpu=future}):
+
+@table @code
+@item int __builtin_saturate_subtract32 (int, int)
+Subtract the second operand from the first operand. If the value
+would be less than 0, then the result is 0 instead of the negative
+value of the subtraction.
+
+@item long __builtin_saturate_subtract64 (long, long)
+Subtract the second operand from the first operand. If the value
+would be less than 0, then the result is 0 instead of the negative
+value of the subtraction.
+@end table
+
@node PowerPC AltiVec/VSX Built-in Functions
@subsection PowerPC AltiVec/VSX Built-in Functions
diff --git a/gcc/testsuite/gcc.target/powerpc/subfus-1.c b/gcc/testsuite/gcc.target/powerpc/subfus-1.c
new file mode 100644
index 00000000000..535e7f8483d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/subfus-1.c
@@ -0,0 +1,32 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target powerpc_future_ok } */
+/* { dg-options "-mdejagnu-cpu=future -O2" } */
+
+/* Test whether the saturating subtract built-in generates subwus for 32-bit
+ subtracts. */
+
+int do_sat_int (int a, int b)
+{
+ return __builtin_saturate_subtract32 (a, b); /* subwus */
+}
+
+int do_sat_int_dot (int a, int b, int *p)
+{
+ int r = __builtin_saturate_subtract32 (a, b); /* subwus. */
+ if (r == 0)
+ *p = 0;
+
+ return r;
+}
+
+void do_sat_int_dot2 (int a, int b, int *p, int *q)
+{
+ if (__builtin_saturate_subtract32 (a, b)) /* subwus. */
+ *p = 0;
+
+ *q = a + b;
+ return;
+}
+
+/* { dg-final { scan-assembler {\msubwus\M} } } */
+/* { dg-final { scan-assembler-not {\msubf\M} } } */
diff --git a/gcc/testsuite/gcc.target/powerpc/subfus-2.c b/gcc/testsuite/gcc.target/powerpc/subfus-2.c
new file mode 100644
index 00000000000..b68e66dd2b0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/subfus-2.c
@@ -0,0 +1,32 @@
+/* { dg-do compile { target lp64 } } */
+/* { dg-require-effective-target powerpc_future_ok } */
+/* { dg-options "-mdejagnu-cpu=future -O2" } */
+
+/* Test whether the saturating subtract built-in generates subwus for 64-bit
+ subtracts. */
+
+long do_sat_long (long a, long b)
+{
+ return __builtin_saturate_subtract64 (a, b); /* subwus */
+}
+
+long do_sat_long_dot (long a, long b, long *p)
+{
+ long r = __builtin_saturate_subtract64 (a, b); /* subwus. */
+ if (r == 0)
+ *p = 0;
+
+ return r;
+}
+
+void do_sat_long_dot2 (long a, long b, long *p, long *q)
+{
+ if (__builtin_saturate_subtract64 (a, b)) /* subwus. */
+ *p = 0;
+
+ *q = a + b;
+ return;
+}
+
+/* { dg-final { scan-assembler {\msubdus\M} } } */
+/* { dg-final { scan-assembler-not {\msubf\M} } } */
--
2.39.1
--
Michael Meissner, IBM
PO Box 98, Ayer, Massachusetts, USA, 01432
email: meissner@linux.ibm.com
next prev parent reply other threads:[~2023-02-03 21:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-03 21:16 [PATCH 0/8] PowerPC future support for Dense Math Michael Meissner
2023-02-03 21:21 ` [PATCH 1/8] PowerPC: Add -mcpu=future Michael Meissner
2023-02-03 21:23 ` [PATCH 1/8] PowerPC: Make -mcpu=future enable -mblock-ops-vector-pair Michael Meissner
2023-02-03 21:25 ` [PATCH 2/8] PowerPC: Add support for accumulators in DMR registers Michael Meissner
2023-02-03 21:27 ` [PATCH 3/8] PowerPC: Make MMA insns support " Michael Meissner
2023-02-03 21:29 ` [PATCH 4/8] PowerPC: Switch to dense math names for all MMA operations Michael Meissner
2023-02-03 21:33 ` [PATCH 6/8] PowerPC: Add support for 1,024 bit DMR registers Michael Meissner
2023-02-03 21:36 ` [PATCH 7/8] Support load/store vector with right length Michael Meissner
2023-02-03 21:37 ` Michael Meissner [this message]
2023-02-06 7:25 ` [PATCH 0/8] PowerPC future support for Dense Math Richard Biener
2023-02-06 18:22 ` Peter Bergner
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