[gcc(refs/users/meissner/heads/work054)] Generate LXVKQ on power10.

Michael Meissner meissner@gcc.gnu.org
Fri Jun 4 01:25:51 GMT 2021


https://gcc.gnu.org/g:ac51d8244f28d7c94edb5ee5595a62cd9de9ea7d

commit ac51d8244f28d7c94edb5ee5595a62cd9de9ea7d
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Jun 3 21:25:35 2021 -0400

    Generate LXVKQ on power10.
    
    This patch generates the LXVKQ instruction to load certain IEEE 128-bit
    constants.
    
    gcc/
    2021-06-03  Michael Meissner  <meissner@linux.ibm.com>
    
            * config/rs6000/constraint.md (eQ): New constraint.
            * config/rs6000/predicates.md (easy_fp_constant): If the constant
            can be loaded with LXVKQ, it is easy.
            (lxvkq_operand): New predicate.
            * config/rs6000/rs6000-protos.h (lxvkq_constant_p): New
            declaration.
            * config/rs6000/rs6000-cpus.h (ISA_3_1_MASKS_SERVER): Add -mlxvkq.
            (POWERPC_MASKS): Add -mlxvkq.
            * config/rs6000/rs6000.c (rs6000_option_override_internal): Add
            support for -mlxvkq.
            (lxvkq_constant_p): New function.
            (output_vec_const_move): Add support for generating lxvkq.
            (rs6000_output_move_128bit): Add support for generating lxvkq.
            (rs6000_opt_masks): Add -mlxvkq.
            * config/rs6000/rs6000.opt (-mlxvkq): New option.
            * config/rs6000/vsx.md (vsx_mov<mode>_64bit): Add support to
            generate lxvkq.
            (vsx_mov<mode>_32bit): Add support to generate lxvkq.
    
    gcc/testsuite/
    2021-06-03  Michael Meissner  <meissner@linux.ibm.com>
    
            * gcc.target/powerpc/float128-constant.c: New test.

Diff:
---
 gcc/config/rs6000/constraints.md                   |   5 +
 gcc/config/rs6000/predicates.md                    |  14 ++
 gcc/config/rs6000/rs6000-cpus.def                  |   2 +
 gcc/config/rs6000/rs6000-protos.h                  |   1 +
 gcc/config/rs6000/rs6000.c                         | 103 ++++++++++++++-
 gcc/config/rs6000/rs6000.opt                       |   4 +
 gcc/config/rs6000/vsx.md                           |  28 ++--
 .../gcc.target/powerpc/float128-constant.c         | 144 +++++++++++++++++++++
 8 files changed, 286 insertions(+), 15 deletions(-)

diff --git a/gcc/config/rs6000/constraints.md b/gcc/config/rs6000/constraints.md
index d665e2a94db..d14ce98e9ac 100644
--- a/gcc/config/rs6000/constraints.md
+++ b/gcc/config/rs6000/constraints.md
@@ -224,6 +224,11 @@
   "A signed 34-bit integer constant if prefixed instructions are supported."
   (match_operand 0 "cint34_operand"))
 
+;; KF/TF scalar than can be loaded with XVKQ
+(define_constraint "eQ"
+  "An IEEE 128-bit constant that can be loaded with the LXVKQ instruction."
+  (match_operand 0 "lxvkq_operand"))
+
 ;; Floating-point constraints.  These two are defined so that insn
 ;; length attributes can be calculated exactly.
 
diff --git a/gcc/config/rs6000/predicates.md b/gcc/config/rs6000/predicates.md
index a81a26cca74..9584663ce16 100644
--- a/gcc/config/rs6000/predicates.md
+++ b/gcc/config/rs6000/predicates.md
@@ -611,6 +611,11 @@
   if (xxsplti32dx_operand (op, mode))
     return 1;
 
+  /* If we have the ISA 3.1 LXVKQ instruction, see if the constant can be loaded
+     with that instruction.  */
+  if (lxvkq_operand (op, mode))
+    return 1;
+
   /* Otherwise consider floating point constants hard, so that the
      constant gets pushed to memory during the early RTL phases.  This
      has the advantage that double precision constants that can be
@@ -699,6 +704,15 @@
   return xxsplti32dx_constant_p (op, mode, &high, &low);
 })
 
+;; Return 1 if the operand is an IEEE 128-bit special constant that can be
+;; loaded with the LXVKQ instruction.
+(define_predicate "lxvkq_operand"
+  (match_code "const_double")
+{
+  int immediate = 0;
+  return lxvkq_constant_p (op, mode, &immediate);
+})
+
 ;; Return 1 if the operand is a CONST_VECTOR and can be loaded into a
 ;; vector register without using memory.
 (define_predicate "easy_vector_constant"
diff --git a/gcc/config/rs6000/rs6000-cpus.def b/gcc/config/rs6000/rs6000-cpus.def
index b8e787714e3..c0d89434fcd 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -83,6 +83,7 @@
 #define ISA_3_1_MASKS_SERVER	(ISA_3_0_MASKS_SERVER			\
 				 | OPTION_MASK_POWER10			\
 				 | OTHER_POWER10_MASKS			\
+				 | OPTION_MASK_LXVKQ			\
 				 | OPTION_MASK_P10_FUSION		\
 				 | OPTION_MASK_P10_FUSION_LD_CMPI	\
 				 | OPTION_MASK_P10_FUSION_2LOGICAL	\
@@ -146,6 +147,7 @@
 				 | OPTION_MASK_P10_FUSION_2ADD    	\
 				 | OPTION_MASK_HTM			\
 				 | OPTION_MASK_ISEL			\
+				 | OPTION_MASK_LXVKQ			\
 				 | OPTION_MASK_MFCRF			\
 				 | OPTION_MASK_MMA			\
 				 | OPTION_MASK_MODULO			\
diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h
index 9e60f027bd5..600d64424f5 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -35,6 +35,7 @@ extern bool xxspltib_constant_p (rtx, machine_mode, int *, int *);
 extern bool xxspltidp_constant_p (rtx, machine_mode, HOST_WIDE_INT *);
 extern bool xxsplti32dx_constant_p (rtx, machine_mode, HOST_WIDE_INT *,
 				    HOST_WIDE_INT *);
+extern bool lxvkq_constant_p (rtx, machine_mode, int *);
 extern int vspltis_shifted (rtx);
 extern HOST_WIDE_INT const_vector_elt_as_int (rtx, unsigned int);
 extern bool macho_lo_sum_memory_operand (rtx, machine_mode);
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 80b63e12013..9db2d595230 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -4511,9 +4511,13 @@ rs6000_option_override_internal (bool global_init_p)
 
       if ((rs6000_isa_flags_explicit & OPTION_MASK_XXSPLTIDP) == 0)
 	rs6000_isa_flags |= OPTION_MASK_XXSPLTIDP;
+
+      if ((rs6000_isa_flags_explicit & OPTION_MASK_LXVKQ) == 0)
+	rs6000_isa_flags |= OPTION_MASK_LXVKQ;
     }
   else
-    rs6000_isa_flags &= ~(OPTION_MASK_XXSPLTIW
+    rs6000_isa_flags &= ~(OPTION_MASK_LXVKQ
+			  | OPTION_MASK_XXSPLTIW
 			  | OPTION_MASK_XXSPLTIDP
 			  | OPTION_MASK_XXSPLTI32DX);
 
@@ -6722,6 +6726,86 @@ xxsplti32dx_constant_p (rtx op,
   return false;
 }
 
+/* Return true if OP is of the given MODE is one of the 18 special values that
+   can be generated with the LXVKQ instruction.
+
+   Return the constant that will go in the LXVKQ instruction.
+
+   The LXVKQ immediates are:
+	1 - 7:		1.0 .. 7.0.
+	8:		Positive infinity.
+	9:		Default quiet NaN.
+	16:		-0.0.
+	17 - 23:	-1.0 .. 7.0.
+	24:		Negative infinity.  */
+
+bool
+lxvkq_constant_p (rtx op,
+		  machine_mode mode,
+		  int *imm_p)
+{
+  *imm_p = -1;
+
+  if (!TARGET_LXVKQ)
+    return false;
+
+  if (mode == VOIDmode)
+    mode = GET_MODE (op);
+
+  if (!FLOAT128_IEEE_P (mode))
+    return false;
+
+  if (!CONST_DOUBLE_P (op))
+    return false;
+
+  /* All of the values generated can be expressed as SFmode values, so if it
+     doesn't fit in SFmode, exit.  */
+  const struct real_value *rv = CONST_DOUBLE_REAL_VALUE (op);
+  if (!exact_real_truncate (SFmode, rv))
+    return 0;
+
+  /* +/- Inifinity  is 8/24.  */
+  if (REAL_VALUE_ISINF (*rv))
+    {
+      *imm_p = real_isneg (rv) ? 24 : 8;
+      return true;
+    }
+
+  /* NaN is 9.  */
+  if (REAL_VALUE_ISNAN (*rv) && !REAL_VALUE_NEGATIVE (*rv))
+    {
+      *imm_p = 9;
+      return true;
+    }
+
+  /* -0.0 is 16.  */
+  if (REAL_VALUE_MINUS_ZERO (*rv))
+    {
+      *imm_p = 16;
+      return true;
+    }
+
+  /* The other values are all integers 1..7, and -1..-7.  */
+  if (!real_isinteger (rv, mode))
+    return false;
+
+  HOST_WIDE_INT value = real_to_integer (rv);
+  if (value >= 1 && value <= 7)
+    {
+      *imm_p = value;
+      return true;
+    }
+  else if (value >= -7 && value <= -1)
+    {
+      /* Subtraction is used because value is negative.  */
+      *imm_p = 16 - value;
+      return true;
+    }
+
+  /* We can't load the value with LXVKQ.  */
+  return false;
+}
+
 const char *
 output_vec_const_move (rtx *operands)
 {
@@ -6738,6 +6822,7 @@ output_vec_const_move (rtx *operands)
       bool dest_vmx_p = ALTIVEC_REGNO_P (REGNO (dest));
       int xxspltib_value = 256;
       int num_insns = -1;
+      int lxvkq_immediate = 0;
 
       if (zero_constant (vec, mode))
 	{
@@ -6773,6 +6858,12 @@ output_vec_const_move (rtx *operands)
       if (xxsplti32dx_operand (vec, mode))
 	return "#";
 
+      if (lxvkq_constant_p (vec, mode, &lxvkq_immediate))
+	{
+	  operands[2] = GEN_INT (lxvkq_immediate);
+	  return "lxvkq %x0,%2";
+	}
+
       if (TARGET_P9_VECTOR
 	  && xxspltib_constant_p (vec, mode, &num_insns, &xxspltib_value))
 	{
@@ -13457,6 +13548,7 @@ rs6000_output_move_128bit (rtx operands[])
   int src_regno;
   bool dest_gpr_p, dest_fp_p, dest_vmx_p, dest_vsx_p;
   bool src_gpr_p, src_fp_p, src_vmx_p, src_vsx_p;
+  int lxvkq_immediate = 0;
 
   if (REG_P (dest))
     {
@@ -13601,6 +13693,14 @@ rs6000_output_move_128bit (rtx operands[])
     }
 
   /* Constants.  */
+  else if (dest_vmx_p
+	   && CONST_DOUBLE_P (src)
+	   && lxvkq_constant_p (src, mode, &lxvkq_immediate))
+    {
+      operands[2] = GEN_INT (lxvkq_immediate);
+      return "lxvkq %x0,%2";
+    }
+
   else if (dest_regno >= 0
 	   && (CONST_INT_P (src)
 	       || CONST_WIDE_INT_P (src)
@@ -24300,6 +24400,7 @@ static struct rs6000_opt_mask const rs6000_opt_masks[] =
   { "hard-dfp",			OPTION_MASK_DFP,		false, true  },
   { "htm",			OPTION_MASK_HTM,		false, true  },
   { "isel",			OPTION_MASK_ISEL,		false, true  },
+  { "lxvkq",			OPTION_MASK_LXVKQ,		false, true  },
   { "mfcrf",			OPTION_MASK_MFCRF,		false, true  },
   { "mfpgpr",			0,				false, true  },
   { "mma",			OPTION_MASK_MMA,		false, true  },
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index e28a81d5fdd..e65dd8762a4 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -651,3 +651,7 @@ Generate (do not generate) XXSPLTIDP instructions.
 mxxsplti32dx
 Target Undocumented Mask(XXSPLTI32DX) Var(rs6000_isa_flags)
 Generate (do not generate) XXSPLTI32DX instructions.
+
+mlxvkq
+Target Undocumented Mask(LXVKQ) Var(rs6000_isa_flags)
+Generate (do not generate) LXVKQ instructions.
diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index 254653d31d5..b49d5b44573 100644
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -1196,17 +1196,17 @@
 
 ;;              VSX store  VSX load   VSX move  VSX->GPR   GPR->VSX    LQ (GPR)
 ;;              STQ (GPR)  GPR load   GPR store GPR move   XXSPLTIB    VSPLTISW
-;;              VSX 0/-1   VMX const  GPR const LVX (VMX)  STVX (VMX)
+;;              VSX 0/-1   VMX const  GPR const LVX (VMX)  STVX (VMX)  LXVKQ
 (define_insn "vsx_mov<mode>_64bit"
   [(set (match_operand:VSX_M 0 "nonimmediate_operand"
                "=ZwO,      wa,        wa,        r,         we,        ?wQ,
                 ?&r,       ??r,       ??Y,       <??r>,     wa,        v,
-                ?wa,       v,         <??r>,     wZ,        v")
+                ?wa,       v,         <??r>,     wZ,        v,         wa")
 
 	(match_operand:VSX_M 1 "input_operand" 
                "wa,        ZwO,       wa,        we,        r,         r,
                 wQ,        Y,         r,         r,         wE,        jwM,
-                ?jwM,      W,         <nW>,      v,         wZ"))]
+                ?jwM,      W,         <nW>,      v,         wZ,        eQ"))]
 
   "TARGET_POWERPC64 && VECTOR_MEM_VSX_P (<MODE>mode)
    && (register_operand (operands[0], <MODE>mode) 
@@ -1217,37 +1217,37 @@
   [(set_attr "type"
                "vecstore,  vecload,   vecsimple, mtvsr,     mfvsr,     load,
                 store,     load,      store,     *,         vecsimple, vecsimple,
-                vecsimple, *,         *,         vecstore,  vecload")
+                vecsimple, *,         *,         vecstore,  vecload,   vecsimple")
    (set_attr "num_insns"
                "*,         *,         *,         2,         *,         2,
                 2,         2,         2,         2,         *,         *,
-                *,         5,         2,         *,         *")
+                *,         5,         2,         *,         *,         *")
    (set_attr "max_prefixed_insns"
                "*,         *,         *,         *,         *,         2,
                 2,         2,         2,         2,         *,         *,
-                *,         *,         *,         *,         *")
+                *,         *,         *,         *,         *,         *")
    (set_attr "length"
                "*,         *,         *,         8,         *,         8,
                 8,         8,         8,         8,         *,         *,
-                *,         20,        8,         *,         *")
+                *,         20,        8,         *,         *,         *")
    (set_attr "isa"
                "<VSisa>,   <VSisa>,   <VSisa>,   *,         *,         *,
                 *,         *,         *,         *,         p9v,       *,
-                <VSisa>,   *,         *,         *,         *")])
+                <VSisa>,   *,         *,         *,         *,         p10")])
 
 ;;              VSX store  VSX load   VSX move   GPR load   GPR store  GPR move
 ;;              XXSPLTIB   VSPLTISW   VSX 0/-1   VMX const  GPR const
-;;              LVX (VMX)  STVX (VMX)
+;;              LVX (VMX)  STVX (VMX) LXVKQ
 (define_insn "*vsx_mov<mode>_32bit"
   [(set (match_operand:VSX_M 0 "nonimmediate_operand"
                "=ZwO,      wa,        wa,        ??r,       ??Y,       <??r>,
                 wa,        v,         ?wa,       v,         <??r>,
-                wZ,        v")
+                wZ,        v,         wa")
 
 	(match_operand:VSX_M 1 "input_operand" 
                "wa,        ZwO,       wa,        Y,         r,         r,
                 wE,        jwM,       ?jwM,      W,         <nW>,
-                v,         wZ"))]
+                v,         wZ,        eQ"))]
 
   "!TARGET_POWERPC64 && VECTOR_MEM_VSX_P (<MODE>mode)
    && (register_operand (operands[0], <MODE>mode) 
@@ -1258,15 +1258,15 @@
   [(set_attr "type"
                "vecstore,  vecload,   vecsimple, load,      store,    *,
                 vecsimple, vecsimple, vecsimple, *,         *,
-                vecstore,  vecload")
+                vecstore,  vecload,   vecsimple")
    (set_attr "length"
                "*,         *,         *,         16,        16,        16,
                 *,         *,         *,         20,        16,
-                *,         *")
+                *,         *,         *")
    (set_attr "isa"
                "<VSisa>,   <VSisa>,   <VSisa>,   *,         *,         *,
                 p9v,       *,         <VSisa>,   *,         *,
-                *,         *")])
+                *,         *,         p10")])
 
 ;; Explicit  load/store expanders for the builtin functions
 (define_expand "vsx_load_<mode>"
diff --git a/gcc/testsuite/gcc.target/powerpc/float128-constant.c b/gcc/testsuite/gcc.target/powerpc/float128-constant.c
new file mode 100644
index 00000000000..a5cbe0b477f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/float128-constant.c
@@ -0,0 +1,144 @@
+/* { dg-require-effective-target ppc_float128_hw } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
+
+/* Test whether the LXVKQ instruction is generated to load special IEEE 128-bit
+   constants.  */
+
+_Float128
+return_0 (void)
+{
+  return 0.0f128;			/* XXSPLTIB 34,0.  */
+}
+
+_Float128
+return_1 (void)
+{
+  return 1.0f128;			/* LXVKQ 34,1.  */
+}
+
+_Float128
+return_2 (void)
+{
+  return 2.0f128;			/* LXVKQ 34,2.  */
+}
+
+_Float128
+return_3 (void)
+{
+  return 3.0f128;			/* LXVKQ 34,3.  */
+}
+
+_Float128
+return_4 (void)
+{
+  return 4.0f128;			/* LXVKQ 34,4.  */
+}
+
+_Float128
+return_5 (void)
+{
+  return 5.0f128;			/* LXVKQ 34,5.  */
+}
+
+_Float128
+return_6 (void)
+{
+  return 6.0f128;			/* LXVKQ 34,6.  */
+}
+
+_Float128
+return_7 (void)
+{
+  return 7.0f128;			/* LXVKQ 34,7.  */
+}
+
+_Float128
+return_m0 (void)
+{
+  return -0.0f128;			/* LXVKQ 34,16.  */
+}
+
+_Float128
+return_m1 (void)
+{
+  return -1.0f128;			/* LXVKQ 34,17.  */
+}
+
+_Float128
+return_m2 (void)
+{
+  return -2.0f128;			/* LXVKQ 34,18.  */
+}
+
+_Float128
+return_m3 (void)
+{
+  return -3.0f128;			/* LXVKQ 34,19.  */
+}
+
+_Float128
+return_m4 (void)
+{
+  return -4.0f128;			/* LXVKQ 34,20.  */
+}
+
+_Float128
+return_m5 (void)
+{
+  return -5.0f128;			/* LXVKQ 34,21.  */
+}
+
+_Float128
+return_m6 (void)
+{
+  return -6.0f128;			/* LXVKQ 34,22.  */
+}
+
+_Float128
+return_m7 (void)
+{
+  return -7.0f128;			/* LXVKQ 34,23.  */
+}
+
+_Float128
+return_inf (void)
+{
+  return __builtin_inff128 ();		/* LXVKQ 34,8.  */
+}
+
+_Float128
+return_minf (void)
+{
+  return - __builtin_inff128 ();	/* LXVKQ 34,24.  */
+}
+
+_Float128
+return_nan (void)
+{
+  return __builtin_nanf128 ("");	/* LXVKQ 34,9.  */
+}
+
+/* Note, the following NaNs should not generate a LXVKQ instruction.  */
+_Float128
+return_mnan (void)
+{
+  return - __builtin_nanf128 ("");	/* PLXV 34,... */
+}
+
+_Float128
+return_nan2 (void)
+{
+  return __builtin_nanf128 ("1");	/* PLXV 34,... */
+}
+
+_Float128
+return_nans (void)
+{
+  return __builtin_nansf128 ("");	/* PLXV 34,... */
+}
+
+/* { dg-final { scan-assembler-times {\mlxvkq\M}    18 } } */
+/* { dg-final { scan-assembler-times {\mplxv\M}      3 } } */
+/* { dg-final { scan-assembler-times {\mxxspltib\M}  1 } } */
+


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