RISC-V: Support zfh and zfhmin extension

Zfh and Zfhmin are extensions for IEEE half precision, both are ratified
in Jan. 2022[1]:

- Zfh has full set of operation like F or D for single or double precision.
- Zfhmin has only provide minimal support for half precision operation,
  like conversion, load, store and move instructions.

[1] https://github.com/riscv/riscv-isa-manual/commit/b35a54079e0da11740ce5b1e6db999d1d5172768

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_implied_info): Add
	zfh and zfhmin.
	(riscv_ext_version_table): Ditto.
	(riscv_ext_flag_table): Ditto.
	* config/riscv/riscv-opts.h (MASK_ZFHMIN): New.
	(MASK_ZFH): Ditto.
	(TARGET_ZFHMIN): Ditto.
	(TARGET_ZFH): Ditto.
	* config/riscv/riscv.cc (riscv_output_move): Handle HFmode move
	for zfh and zfhmin.
	(riscv_emit_float_compare): Handle HFmode.
	* config/riscv/riscv.md (ANYF): Add HF.
	(SOFTF): Add HF.
	(load): Ditto.
	(store): Ditto.
	(truncsfhf2): New.
	(truncdfhf2): Ditto.
	(extendhfsf2): Ditto.
	(extendhfdf2): Ditto.
	(*movhf_hardfloat): Ditto.
	(*movhf_softfloat): Make sure not ZFHMIN.
	* config/riscv/riscv.opt (riscv_zf_subext): New.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/_Float16-zfh-1.c: New.
	* gcc.target/riscv/_Float16-zfh-2.c: Ditto.
	* gcc.target/riscv/_Float16-zfh-3.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-1.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-2.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-3.c: Ditto.
	* gcc.target/riscv/arch-16.c: Ditto.
	* gcc.target/riscv/arch-17.c: Ditto.
	* gcc.target/riscv/predef-21.c: Ditto.
	* gcc.target/riscv/predef-22.c: Ditto.

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 0e5be2ce105dcf2410d5273d385c3558daa9c29b..4ee1b3198c505965b355eb59e9507aab99b6a2d8 100644 (file)
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -96,6 +96,9 @@ static const riscv_implied_info_t riscv_implied_info[] =
   {"zvl32768b", "zvl16384b"},
   {"zvl65536b", "zvl32768b"},
 
+  {"zfh", "zfhmin"},
+  {"zfhmin", "f"},
+
   {NULL, NULL}
 };
 
@@ -193,6 +196,9 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
   {"zvl32768b", ISA_SPEC_CLASS_NONE, 1, 0},
   {"zvl65536b", ISA_SPEC_CLASS_NONE, 1, 0},
 
+  {"zfh",       ISA_SPEC_CLASS_NONE, 1, 0},
+  {"zfhmin",    ISA_SPEC_CLASS_NONE, 1, 0},
+
   /* Terminate the list.  */
   {NULL, ISA_SPEC_CLASS_NONE, 0, 0}
 };
@@ -1148,6 +1154,8 @@ static const riscv_ext_flag_table_t riscv_ext_flag_table[] =
   {"zvl32768b", &gcc_options::x_riscv_zvl_flags, MASK_ZVL32768B},
   {"zvl65536b", &gcc_options::x_riscv_zvl_flags, MASK_ZVL65536B},
 
+  {"zfhmin",    &gcc_options::x_riscv_zf_subext, MASK_ZFHMIN},
+  {"zfh",       &gcc_options::x_riscv_zf_subext, MASK_ZFH},
 
   {NULL, NULL, 0}
 };

diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
index 1e153b3a6e71911ef704a03f38e69b8ef20b9527..85e869e62e3ad16d82deb20248828290f3ef74cd 100644 (file)
--- a/gcc/config/riscv/riscv-opts.h
+++ b/gcc/config/riscv/riscv-opts.h
@@ -153,6 +153,12 @@ enum stack_protector_guard {
 #define TARGET_ZICBOM ((riscv_zicmo_subext & MASK_ZICBOM) != 0)
 #define TARGET_ZICBOP ((riscv_zicmo_subext & MASK_ZICBOP) != 0)
 
+#define MASK_ZFHMIN   (1 << 0)
+#define MASK_ZFH      (1 << 1)
+
+#define TARGET_ZFHMIN ((riscv_zf_subext & MASK_ZFHMIN) != 0)
+#define TARGET_ZFH    ((riscv_zf_subext & MASK_ZFH) != 0)
+
 /* Bit of riscv_zvl_flags will set contintuly, N-1 bit will set if N-bit is
    set, e.g. MASK_ZVL64B has set then MASK_ZVL32B is set, so we can use
    popcount to caclulate the minimal VLEN.  */

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 47e6110767c4275486e6c3c051e51c9f5a860c56..9d70974c893f2d189ca326296f56d0aea9f19eda 100644 (file)
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -2313,6 +2313,8 @@ riscv_output_move (rtx dest, rtx src)
        switch (width)
          {
          case 2:
+           if (TARGET_ZFHMIN)
+             return "fmv.x.h\t%0,%1";
            /* Using fmv.x.s + sign-extend to emulate fmv.x.h.  */
            return "fmv.x.s\t%0,%1;slli\t%0,%0,16;srai\t%0,%0,16";
          case 4:
@@ -2367,6 +2369,8 @@ riscv_output_move (rtx dest, rtx src)
            switch (width)
              {
              case 2:
+               if (TARGET_ZFHMIN)
+                 return "fmv.h.x\t%0,%z1";
                /* High 16 bits should be all-1, otherwise HW will treated
                   as a n-bit canonical NaN, but isn't matter for softfloat.  */
                return "fmv.s.x\t%0,%1";
@@ -2395,6 +2399,8 @@ riscv_output_move (rtx dest, rtx src)
        switch (width)
          {
          case 2:
+           if (TARGET_ZFH)
+             return "fmv.h\t%0,%1";
            return "fmv.s\t%0,%1";
          case 4:
            return "fmv.s\t%0,%1";
@@ -2403,12 +2409,28 @@ riscv_output_move (rtx dest, rtx src)
          }
 
       if (dest_code == MEM)
-       return dbl_p ? "fsd\t%1,%0" : "fsw\t%1,%0";
+       switch (width)
+         {
+         case 2:
+           return "fsh\t%1,%0";
+         case 4:
+           return "fsw\t%1,%0";
+         case 8:
+           return "fsd\t%1,%0";
+         }
     }
   if (dest_code == REG && FP_REG_P (REGNO (dest)))
     {
       if (src_code == MEM)
-       return dbl_p ? "fld\t%0,%1" : "flw\t%0,%1";
+       switch (width)
+         {
+         case 2:
+           return "flh\t%0,%1";
+         case 4:
+           return "flw\t%0,%1";
+         case 8:
+           return "fld\t%0,%1";
+         }
     }
   gcc_unreachable ();
 }
@@ -2685,6 +2707,10 @@ riscv_emit_float_compare (enum rtx_code *code, rtx *op0, rtx *op1)
        emit_insn (gen_f##CMP##_quietdfdi4 (*op0, cmp_op0, cmp_op1));   \
       else if (GET_MODE (cmp_op0) == DFmode)                           \
        emit_insn (gen_f##CMP##_quietdfsi4 (*op0, cmp_op0, cmp_op1));   \
+      else if (GET_MODE (cmp_op0) == HFmode && TARGET_64BIT)           \
+       emit_insn (gen_f##CMP##_quiethfdi4 (*op0, cmp_op0, cmp_op1));   \
+      else if (GET_MODE (cmp_op0) == HFmode)                           \
+       emit_insn (gen_f##CMP##_quiethfsi4 (*op0, cmp_op0, cmp_op1));   \
       else                                                             \
        gcc_unreachable ();                                             \
       *op1 = const0_rtx;                                               \
@@ -5722,7 +5748,8 @@ riscv_excess_precision (enum excess_precision_type type)
     {
     case EXCESS_PRECISION_TYPE_FAST:
     case EXCESS_PRECISION_TYPE_STANDARD:
-      return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT;
+      return (TARGET_ZFH ? FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16
+                        : FLT_EVAL_METHOD_PROMOTE_TO_FLOAT);
     case EXCESS_PRECISION_TYPE_IMPLICIT:
       return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16;
     default:

diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 7af5c90e0f3f62d9b476b08fa88086c92671f3fd..493f00cdb80bf609528967dc5d7312568c9b66da 100644 (file)
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -307,17 +307,18 @@
 
 ;; Iterator for hardware-supported floating-point modes.
 (define_mode_iterator ANYF [(SF "TARGET_HARD_FLOAT")
-                           (DF "TARGET_DOUBLE_FLOAT")])
+                           (DF "TARGET_DOUBLE_FLOAT")
+                           (HF "TARGET_ZFH")])
 
 ;; Iterator for floating-point modes that can be loaded into X registers.
-(define_mode_iterator SOFTF [SF (DF "TARGET_64BIT")])
+(define_mode_iterator SOFTF [SF (DF "TARGET_64BIT") (HF "TARGET_ZFHMIN")])
 
 ;; This attribute gives the length suffix for a sign- or zero-extension
 ;; instruction.
 (define_mode_attr size [(QI "b") (HI "h")])
 
 ;; Mode attributes for loads.
-(define_mode_attr load [(QI "lb") (HI "lh") (SI "lw") (DI "ld") (SF "flw") (DF "fld")])
+(define_mode_attr load [(QI "lb") (HI "lh") (SI "lw") (DI "ld") (HF "flh") (SF "flw") (DF "fld")])
 
 ;; Instruction names for integer loads that aren't explicitly sign or zero
 ;; extended.  See riscv_output_move and LOAD_EXTEND_OP.
@@ -327,7 +328,7 @@
 (define_mode_attr softload [(HF "lh") (SF "lw") (DF "ld")])
 
 ;; Instruction names for stores.
-(define_mode_attr store [(QI "sb") (HI "sh") (SI "sw") (DI "sd") (SF "fsw") (DF "fsd")])
+(define_mode_attr store [(QI "sb") (HI "sh") (SI "sw") (DI "sd") (HF "fsh") (SF "fsw") (DF "fsd")])
 
 ;; Instruction names for FP stores from integer registers.
 (define_mode_attr softstore [(HF "sh") (SF "sw") (DF "sd")])
@@ -1324,6 +1325,24 @@
   [(set_attr "type" "fcvt")
    (set_attr "mode" "SF")])
 
+(define_insn "truncsfhf2"
+  [(set (match_operand:HF     0 "register_operand" "=f")
+       (float_truncate:HF
+           (match_operand:SF 1 "register_operand" " f")))]
+  "TARGET_ZFHMIN"
+  "fcvt.h.s\t%0,%1"
+  [(set_attr "type" "fcvt")
+   (set_attr "mode" "HF")])
+
+(define_insn "truncdfhf2"
+  [(set (match_operand:HF     0 "register_operand" "=f")
+       (float_truncate:HF
+           (match_operand:DF 1 "register_operand" " f")))]
+  "TARGET_ZFHMIN && TARGET_DOUBLE_FLOAT"
+  "fcvt.h.d\t%0,%1"
+  [(set_attr "type" "fcvt")
+   (set_attr "mode" "HF")])
+
 ;;
 ;;  ....................
 ;;
@@ -1441,6 +1460,15 @@
   [(set_attr "move_type" "shift_shift,load")
    (set_attr "mode" "SI")])
 
+(define_insn "extendhfsf2"
+  [(set (match_operand:SF     0 "register_operand" "=f")
+       (float_extend:SF
+           (match_operand:HF 1 "register_operand" " f")))]
+  "TARGET_ZFHMIN"
+  "fcvt.s.h\t%0,%1"
+  [(set_attr "type" "fcvt")
+   (set_attr "mode" "SF")])
+
 (define_insn "extendsfdf2"
   [(set (match_operand:DF     0 "register_operand" "=f")
        (float_extend:DF
@@ -1450,6 +1478,15 @@
   [(set_attr "type" "fcvt")
    (set_attr "mode" "DF")])
 
+(define_insn "extendhfdf2"
+  [(set (match_operand:DF     0 "register_operand" "=f")
+       (float_extend:DF
+           (match_operand:HF 1 "register_operand" " f")))]
+  "TARGET_ZFHMIN && TARGET_DOUBLE_FLOAT"
+  "fcvt.d.h\t%0,%1"
+  [(set_attr "type" "fcvt")
+   (set_attr "mode" "DF")])
+
 ;; 16-bit floating point moves
 (define_expand "movhf"
   [(set (match_operand:HF 0 "")
@@ -1460,12 +1497,22 @@
     DONE;
 })
 
+(define_insn "*movhf_hardfloat"
+  [(set (match_operand:HF 0 "nonimmediate_operand" "=f,f,f,m,m,*f,*r,  *r,*r,*m")
+       (match_operand:HF 1 "move_operand"         " f,G,m,f,G,*r,*f,*G*r,*m,*r"))]
+  "TARGET_ZFHMIN
+   && (register_operand (operands[0], HFmode)
+       || reg_or_0_operand (operands[1], HFmode))"
+  { return riscv_output_move (operands[0], operands[1]); }
+  [(set_attr "move_type" "fmove,mtc,fpload,fpstore,store,mtc,mfc,move,load,store")
+   (set_attr "mode" "HF")])
 
 (define_insn "*movhf_softfloat"
   [(set (match_operand:HF 0 "nonimmediate_operand" "=f, r,r,m,*f,*r")
        (match_operand:HF 1 "move_operand"         " f,Gr,m,r,*r,*f"))]
-  "(register_operand (operands[0], HFmode)
-    || reg_or_0_operand (operands[1], HFmode))"
+  "!TARGET_ZFHMIN
+   && (register_operand (operands[0], HFmode)
+       || reg_or_0_operand (operands[1], HFmode))"
   { return riscv_output_move (operands[0], operands[1]); }
   [(set_attr "move_type" "fmove,move,load,store,mtc,mfc")
    (set_attr "mode" "HF")])

diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index 9e9fe6d8ccd1722cfd1e6c5881da3081e31204fc..fbca91b956c60643564e8ae33d67477904a41a98 100644 (file)
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -212,6 +212,9 @@ int riscv_zvl_flags
 TargetVariable
 int riscv_zicmo_subext
 
+TargetVariable
+int riscv_zf_subext
+
 Enum
 Name(isa_spec_class) Type(enum riscv_isa_spec_class)
 Supported ISA specs (for use with the -misa-spec= option):

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfh-1.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-1.c
new file mode 100644 (file)
index 0000000..98908dc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfh -mabi=lp64f -O" } */
+
+_Float16 foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-times "fmv.h" 1 } } */
+    return b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfh-2.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-2.c
new file mode 100644 (file)
index 0000000..58bfa6b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfh -mabi=lp64f -O" } */
+
+_Float16 foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-times "fadd.h" 1 } } */
+    return a + b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfh-3.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-3.c
new file mode 100644 (file)
index 0000000..128b4e5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfh-3.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfh -mabi=lp64f -O" } */
+
+int foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-times "fgt.h" 1 } } */
+    return a > b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-1.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-1.c
new file mode 100644 (file)
index 0000000..631a049
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfhmin -mabi=lp64f -O" } */
+
+_Float16 foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-not "fmv.h" } } */
+    /* { dg-final { scan-assembler-times "fmv.s" 1 } } */
+    return b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-2.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-2.c
new file mode 100644 (file)
index 0000000..06c85eb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-2.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfhmin -mabi=lp64f -O" } */
+
+_Float16 foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-not "fadd.h" } } */
+    /* { dg-final { scan-assembler-times "fadd.s" 1 } } */
+    return a + b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-3.c b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-3.c
new file mode 100644 (file)
index 0000000..28960d6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/_Float16-zfhmin-3.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64if_zfhmin -mabi=lp64f -O" } */
+
+int foo1 (_Float16 a, _Float16 b)
+{
+    /* { dg-final { scan-assembler-not "fgt.h" } } */
+    /* { dg-final { scan-assembler-times "fgt.s" 1 } } */
+    return a > b;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/arch-16.c b/gcc/testsuite/gcc.target/riscv/arch-16.c
new file mode 100644 (file)
index 0000000..14b40ae
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-16.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv32gcv_zfh -mabi=ilp32 -mcmodel=medlow" } */
+int foo()
+{
+}

diff --git a/gcc/testsuite/gcc.target/riscv/arch-17.c b/gcc/testsuite/gcc.target/riscv/arch-17.c
new file mode 100644 (file)
index 0000000..3d3275e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/arch-17.c
@@ -0,0 +1,5 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv32gcv_zfhmin -mabi=ilp32 -mcmodel=medlow" } */
+int foo()
+{
+}

diff --git a/gcc/testsuite/gcc.target/riscv/predef-21.c b/gcc/testsuite/gcc.target/riscv/predef-21.c
new file mode 100644 (file)
index 0000000..a171b3b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/predef-21.c
@@ -0,0 +1,59 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv64i_zfh -mabi=lp64f -mcmodel=medlow -misa-spec=20191213" } */
+
+int main () {
+
+#ifndef __riscv_arch_test
+#error "__riscv_arch_test"
+#endif
+
+#if __riscv_xlen != 64
+#error "__riscv_xlen"
+#endif
+
+#if !defined(__riscv_i)
+#error "__riscv_i"
+#endif
+
+#if defined(__riscv_c)
+#error "__riscv_c"
+#endif
+
+#if defined(__riscv_e)
+#error "__riscv_e"
+#endif
+
+#if defined(__riscv_a)
+#error "__riscv_a"
+#endif
+
+#if defined(__riscv_m)
+#error "__riscv_m"
+#endif
+
+#if !defined(__riscv_f)
+#error "__riscv_f"
+#endif
+
+#if defined(__riscv_d)
+#error "__riscv_d"
+#endif
+
+#if defined(__riscv_v)
+#error "__riscv_v"
+#endif
+
+#if !defined(__riscv_zfh)
+#error "__riscv_zfh"
+#endif
+
+#if !defined(__riscv_zfhmin)
+#error "__riscv_zfhmin"
+#endif
+
+#if !defined(__riscv_zicsr)
+#error "__riscv_zicsr"
+#endif
+
+  return 0;
+}

diff --git a/gcc/testsuite/gcc.target/riscv/predef-22.c b/gcc/testsuite/gcc.target/riscv/predef-22.c
new file mode 100644 (file)
index 0000000..ad18965
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/predef-22.c
@@ -0,0 +1,59 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=rv64i_zfhmin -mabi=lp64f -mcmodel=medlow -misa-spec=20191213" } */
+
+int main () {
+
+#ifndef __riscv_arch_test
+#error "__riscv_arch_test"
+#endif
+
+#if __riscv_xlen != 64
+#error "__riscv_xlen"
+#endif
+
+#if !defined(__riscv_i)
+#error "__riscv_i"
+#endif
+
+#if defined(__riscv_c)
+#error "__riscv_c"
+#endif
+
+#if defined(__riscv_e)
+#error "__riscv_e"
+#endif
+
+#if defined(__riscv_a)
+#error "__riscv_a"
+#endif
+
+#if defined(__riscv_m)
+#error "__riscv_m"
+#endif
+
+#if !defined(__riscv_f)
+#error "__riscv_f"
+#endif
+
+#if defined(__riscv_d)
+#error "__riscv_d"
+#endif
+
+#if defined(__riscv_v)
+#error "__riscv_v"
+#endif
+
+#if defined(__riscv_zfh)
+#error "__riscv_zfh"
+#endif
+
+#if !defined(__riscv_zfhmin)
+#error "__riscv_zfhmin"
+#endif
+
+#if !defined(__riscv_zicsr)
+#error "__riscv_zicsr"
+#endif
+
+  return 0;
+}