RISC-V: Add autovec FP widening/narrowing.

This patch adds FP widening and narrowing expanders as well as tests.
Conceptually similar to integer extension/truncation, we emulate
_Float16 -> double by two vfwcvts and double -> _Float16 by two vfncvts.

gcc/ChangeLog:

	* config/riscv/autovec.md (extend<v_double_trunc><mode>2): New
	expander.
	(extend<v_quad_trunc><mode>2): Ditto.
	(trunc<mode><v_double_trunc>2): Ditto.
	(trunc<mode><v_quad_trunc>2): Ditto.
	* config/riscv/vector-iterators.md: Add VQEXTF and HF to
	V_QUAD_TRUNC and v_quad_trunc.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/conversions/vfncvt-run.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv32gcv.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv64gcv.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfncvt-template.h: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfncvt-zvfh-run.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfwcvt-run.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv32gcv.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv64gcv.c: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfwcvt-template.h: New test.
	* gcc.target/riscv/rvv/autovec/conversions/vfwcvt-zvfh-run.c: New test.

12 files changed, 292 insertions, 2 deletions

diff --git a/gcc/config/riscv/autovec.md b/gcc/config/riscv/autovec.md
index b0e5950..a7c8056 100644
--- a/gcc/config/riscv/autovec.md
+++ b/gcc/config/riscv/autovec.md
@@ -162,12 +162,12 @@
   riscv_vector::emit_vlmax_insn (code_for_pred_scalar (<CODE>, <MODE>mode),
 				 riscv_vector::RVV_BINOP, operands);
   DONE;
-}  
+}
  [(set_attr "type" "vshift")
   (set_attr "mode" "<MODE>")])
 
 ;; -------------------------------------------------------------------------
-;; ---- [INT] Binary shifts by scalar.
+;; ---- [INT] Binary shifts by vector.
 ;; -------------------------------------------------------------------------
 ;; Includes:
 ;; - vsll.vv/vsra.vv/vsrl.vv
@@ -428,6 +428,90 @@
   DONE;
 })
 
+;; -------------------------------------------------------------------------
+;; ---- [FP] Widening.
+;; -------------------------------------------------------------------------
+;; - vfwcvt.f.f.v
+;; -------------------------------------------------------------------------
+(define_insn_and_split "extend<v_double_trunc><mode>2"
+  [(set (match_operand:VWEXTF_ZVFHMIN 0 "register_operand" "=&vr")
+    (float_extend:VWEXTF_ZVFHMIN
+     (match_operand:<V_DOUBLE_TRUNC>  1 "register_operand" "  vr")))]
+  "TARGET_VECTOR && can_create_pseudo_p ()"
+  "#"
+  "&& 1"
+  [(const_int 0)]
+{
+  insn_code icode = code_for_pred_extend (<MODE>mode);
+  riscv_vector::emit_vlmax_insn (icode, riscv_vector::RVV_UNOP, operands);
+  DONE;
+}
+  [(set_attr "type" "vfwcvtftof")
+   (set_attr "mode" "<MODE>")])
+
+(define_expand "extend<v_quad_trunc><mode>2"
+  [(set (match_operand:VQEXTF 0 "register_operand")
+    (float_extend:VQEXTF
+     (match_operand:<V_QUAD_TRUNC> 1 "register_operand")))]
+  "TARGET_VECTOR && (TARGET_ZVFHMIN || TARGET_ZVFH)"
+{
+  rtx dblw = gen_reg_rtx (<V_DOUBLE_TRUNC>mode);
+  insn_code icode = code_for_pred_extend (<V_DOUBLE_TRUNC>mode);
+  rtx ops1[] = {dblw, operands[1]};
+  riscv_vector::emit_vlmax_insn (icode, riscv_vector::RVV_UNOP, ops1);
+
+  icode = code_for_pred_extend (<MODE>mode);
+  rtx ops2[] = {operands[0], dblw};
+  riscv_vector::emit_vlmax_insn (icode, riscv_vector::RVV_UNOP, ops2);
+  DONE;
+})
+
+;; -------------------------------------------------------------------------
+;; ---- [FP] Narrowing.
+;; -------------------------------------------------------------------------
+;; - vfncvt.f.f.w
+;; -------------------------------------------------------------------------
+(define_insn_and_split "trunc<mode><v_double_trunc>2"
+  [(set (match_operand:<V_DOUBLE_TRUNC> 0 "register_operand" "=vr")
+    (truncate:<V_DOUBLE_TRUNC>
+     (match_operand:VWEXTF_ZVFHMIN 1 "register_operand"      " vr")))]
+  "TARGET_VECTOR && can_create_pseudo_p ()"
+  "#"
+  "&& 1"
+  [(const_int 0)]
+{
+  insn_code icode = code_for_pred_trunc (<MODE>mode);
+  riscv_vector::emit_vlmax_fp_insn (icode, riscv_vector::RVV_UNOP, operands);
+  DONE;
+}
+  [(set_attr "type" "vfncvtftof")
+   (set_attr "mode" "<MODE>")])
+
+;; -------------------------------------------------------------------------
+;; Narrowing to a mode whose inner mode size is a quarter of mode's.
+;; We emulate this with two consecutive vfncvts.
+;; -------------------------------------------------------------------------
+(define_expand "trunc<mode><v_quad_trunc>2"
+  [(set (match_operand:<V_QUAD_TRUNC> 0 "register_operand")
+    (truncate:<V_QUAD_TRUNC>
+     (match_operand:VQEXTF 1 "register_operand")))]
+  "TARGET_VECTOR && (TARGET_ZVFHMIN || TARGET_ZVFH)"
+{
+  rtx half = gen_reg_rtx (<V_DOUBLE_TRUNC>mode);
+  rtx opshalf[] = {half, operands[1]};
+
+  /* According to the RISC-V V Spec 13.19. we need to use
+     vfncvt.rod.f.f.w for all steps but the last.  */
+  insn_code icode = code_for_pred_rod_trunc (<MODE>mode);
+  riscv_vector::emit_vlmax_insn (icode, riscv_vector::RVV_UNOP, opshalf);
+
+  rtx ops[] = {operands[0], half};
+  icode = code_for_pred_trunc (<V_DOUBLE_TRUNC>mode);
+  riscv_vector::emit_vlmax_fp_insn (icode, riscv_vector::RVV_UNOP, ops);
+  DONE;
+})
+
+
 ;; =========================================================================
 ;; == Conversions
 ;; =========================================================================
diff --git a/gcc/config/riscv/vector-iterators.md b/gcc/config/riscv/vector-iterators.md
index 7893aa6..8134bc0 100644
--- a/gcc/config/riscv/vector-iterators.md
+++ b/gcc/config/riscv/vector-iterators.md
@@ -547,6 +547,14 @@
   (VNx16DI "TARGET_VECTOR_ELEN_64 && TARGET_MIN_VLEN >= 128")
 ])
 
+(define_mode_iterator VQEXTF [
+  (VNx1DF "TARGET_VECTOR_ELEN_FP_64 && TARGET_MIN_VLEN < 128")
+  (VNx2DF "TARGET_VECTOR_ELEN_FP_64")
+  (VNx4DF "TARGET_VECTOR_ELEN_FP_64")
+  (VNx8DF "TARGET_VECTOR_ELEN_FP_64")
+  (VNx16DF "TARGET_VECTOR_ELEN_FP_64 && TARGET_MIN_VLEN >= 128")
+])
+
 (define_mode_iterator VOEXTI [
   (VNx1DI "TARGET_VECTOR_ELEN_64 && TARGET_MIN_VLEN < 128") (VNx2DI "TARGET_VECTOR_ELEN_64")
   (VNx4DI "TARGET_VECTOR_ELEN_64") (VNx8DI "TARGET_VECTOR_ELEN_64")
@@ -1305,6 +1313,9 @@
   (VNx16SI "VNx16QI") (VNx32SI "VNx32QI")
   (VNx1DI "VNx1HI") (VNx2DI "VNx2HI")
   (VNx4DI "VNx4HI") (VNx8DI "VNx8HI") (VNx16DI "VNx16HI")
+
+  (VNx1DF "VNx1HF") (VNx2DF "VNx2HF") (VNx4DF "VNx4HF") (VNx8DF "VNx8HF")
+  (VNx16DF "VNx16HF")
 ])
 
 (define_mode_attr V_OCT_TRUNC [
@@ -1330,6 +1341,9 @@
   (VNx16SI "vnx16qi") (VNx32SI "vnx32qi")
   (VNx1DI "vnx1hi") (VNx2DI "vnx2hi") (VNx4DI "vnx4hi") (VNx8DI "vnx8hi")
   (VNx16DI "vnx16hi")
+
+  (VNx1DF "vnx1hf") (VNx2DF "vnx2hf") (VNx4DF "vnx4hf") (VNx8DF "vnx8hf")
+  (VNx16DF "vnx16hf")
 ])
 
 (define_mode_attr v_oct_trunc [
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-run.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-run.c
new file mode 100644
index 0000000..65d2826
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-run.c
@@ -0,0 +1,33 @@
+/* { dg-do run { target { riscv_vector } } } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfncvt-template.h"
+
+#include <assert.h>
+
+#define SZ 512
+#define EPS 1e-4
+
+#define RUN(TYPE1,TYPE2)				\
+  TYPE1 src##TYPE1##TYPE2[SZ];				\
+  TYPE2 dst##TYPE1##TYPE2[SZ];				\
+  for (int i = 0; i < SZ; i++)				\
+  {                             			\
+    src##TYPE1##TYPE2[i] = (i & 1) ? -i : i;  		\
+    src##TYPE1##TYPE2[i] *= 3.141592;			\
+    dst##TYPE1##TYPE2[i] = -1;				\
+  }                             			\
+  vfncvt_##TYPE1##TYPE2 (dst##TYPE1##TYPE2,		\
+			src##TYPE1##TYPE2, SZ);		\
+  for (int i = 0; i < SZ; i++)				\
+    assert (__builtin_fabs (dst##TYPE1##TYPE2[i]	\
+	    - ((i & 1) ? -i : i) * 3.141592) < EPS);	\
+
+
+#define RUN_ALL()					\
+ RUN(double, float)					\
+
+int main ()
+{
+  RUN_ALL()
+}
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv32gcv.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv32gcv.c
new file mode 100644
index 0000000..10fe75d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv32gcv.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model -march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfncvt-template.h"
+
+/* { dg-final { scan-assembler-times {\tvfncvt\.f\.f\.w} 3 } } */
+/* { dg-final { scan-assembler-times {\tvfncvt\.rod\.f\.f\.w} 1 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv64gcv.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv64gcv.c
new file mode 100644
index 0000000..fd40fa2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-rv64gcv.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model -march=rv64gcv_zvfh -mabi=lp64d --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfncvt-template.h"
+
+/* { dg-final { scan-assembler-times {\tvfncvt\.f\.f\.w} 3 } } */
+/* { dg-final { scan-assembler-times {\tvfncvt\.rod\.f\.f\.w} 1 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-template.h b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-template.h
new file mode 100644
index 0000000..221e883
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-template.h
@@ -0,0 +1,16 @@
+#include <stdint-gcc.h>
+
+#define TEST(TYPE1, TYPE2)					\
+  __attribute__((noipa))					\
+  void vfncvt_##TYPE1##TYPE2 (TYPE2 *dst, TYPE1 *a, int n)	\
+  {								\
+    for (int i = 0; i < n; i++)					\
+      dst[i] = (TYPE2)a[i];					\
+  }
+
+#define TEST_ALL()						\
+ TEST(float, _Float16)						\
+ TEST(double, _Float16)						\
+ TEST(double, float)						\
+
+TEST_ALL()
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-zvfh-run.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-zvfh-run.c
new file mode 100644
index 0000000..38e0d84
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfncvt-zvfh-run.c
@@ -0,0 +1,34 @@
+/* { dg-do run { target { riscv_vector && riscv_zvfh_hw } } } */
+/* { dg-additional-options "-std=c99 -march=rv64gcv_zvfh -mabi=lp64d -fno-vect-cost-model --param=riscv-autovec-preference=scalable" } */
+
+#include "vfncvt-template.h"
+
+#include <assert.h>
+
+#define SZ 512
+#define EPS 1e-4
+
+#define RUN(TYPE1,TYPE2)					\
+  TYPE1 src##TYPE1##TYPE2[SZ];					\
+  TYPE2 dst##TYPE1##TYPE2[SZ];					\
+  for (int i = 0; i < SZ; i++)					\
+  {                             				\
+    src##TYPE1##TYPE2[i] = (i & 1) ? -i : i;  			\
+    src##TYPE1##TYPE2[i] *= 0.0003141592;			\
+    dst##TYPE1##TYPE2[i] = -1;					\
+  }                             				\
+  vfncvt_##TYPE1##TYPE2 (dst##TYPE1##TYPE2,			\
+			src##TYPE1##TYPE2, SZ);			\
+  for (int i = 0; i < SZ; i++)					\
+    assert (__builtin_fabs (dst##TYPE1##TYPE2[i]		\
+	    - ((i & 1) ? -i : i) * 0.0003141592) < EPS);	\
+
+
+#define RUN_ALL()						\
+ RUN(float, _Float16)						\
+ RUN(double, _Float16)						\
+
+int main ()
+{
+  RUN_ALL()
+}
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-run.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-run.c
new file mode 100644
index 0000000..9594909
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-run.c
@@ -0,0 +1,33 @@
+/* { dg-do run { target { riscv_vector } } } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfwcvt-template.h"
+
+#include <assert.h>
+
+#define SZ 512
+#define EPS 1e-4
+
+#define RUN(TYPE1,TYPE2)				\
+  TYPE1 src##TYPE1##TYPE2[SZ];				\
+  TYPE2 dst##TYPE1##TYPE2[SZ];				\
+  for (int i = 0; i < SZ; i++)				\
+  {                             			\
+    src##TYPE1##TYPE2[i] = (i & 1) ? -i : i;  		\
+    src##TYPE1##TYPE2[i] *= 3.141592;			\
+    dst##TYPE1##TYPE2[i] = -1;				\
+  }                             			\
+  vfwcvt_##TYPE1##TYPE2 (dst##TYPE1##TYPE2,		\
+			src##TYPE1##TYPE2, SZ);		\
+  for (int i = 0; i < SZ; i++)				\
+    assert (__builtin_fabs (dst##TYPE1##TYPE2[i]	\
+	    - ((i & 1) ? -i : i) * 3.141592) < EPS);	\
+
+
+#define RUN_ALL()					\
+ RUN(float, double)					\
+
+int main ()
+{
+  RUN_ALL()
+}
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv32gcv.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv32gcv.c
new file mode 100644
index 0000000..006bdb2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv32gcv.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model -march=rv32gcv_zvfh -mabi=ilp32d --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfwcvt-template.h"
+
+/* { dg-final { scan-assembler-times {\tvfwcvt\.f\.f\.v} 4 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv64gcv.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv64gcv.c
new file mode 100644
index 0000000..7ec7107
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-rv64gcv.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-std=c99 -fno-vect-cost-model -march=rv64gcv_zvfh -mabi=lp64d --param=riscv-autovec-preference=fixed-vlmax" } */
+
+#include "vfwcvt-template.h"
+
+/* { dg-final { scan-assembler-times {\tvfwcvt\.f\.f\.v} 4 } } */
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-template.h b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-template.h
new file mode 100644
index 0000000..b6ccf3b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-template.h
@@ -0,0 +1,16 @@
+#include <stdint-gcc.h>
+
+#define TEST(TYPE1, TYPE2)					\
+  __attribute__((noipa))					\
+  void vfwcvt_##TYPE1##TYPE2 (TYPE2 *dst, TYPE1 *a, int n)	\
+  {								\
+    for (int i = 0; i < n; i++)					\
+      dst[i] = (TYPE2)a[i];					\
+  }
+
+#define TEST_ALL()						\
+ TEST(_Float16, float)						\
+ TEST(_Float16, double)						\
+ TEST(float, double)						\
+
+TEST_ALL()
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-zvfh-run.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-zvfh-run.c
new file mode 100644
index 0000000..77d653e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/conversions/vfwcvt-zvfh-run.c
@@ -0,0 +1,34 @@
+/* { dg-do run { target { riscv_vector && riscv_zvfh_hw } } } */
+/* { dg-additional-options "-std=c99 -march=rv64gcv_zvfh -mabi=lp64d -fno-vect-cost-model --param=riscv-autovec-preference=scalable" } */
+
+#include "vfwcvt-template.h"
+
+#include <assert.h>
+
+#define SZ 512
+#define EPS 1e-4
+
+#define RUN(TYPE1,TYPE2)					\
+  TYPE1 src##TYPE1##TYPE2[SZ];					\
+  TYPE2 dst##TYPE1##TYPE2[SZ];					\
+  for (int i = 0; i < SZ; i++)					\
+  {                             				\
+    src##TYPE1##TYPE2[i] = (i & 1) ? -i : i;  			\
+    src##TYPE1##TYPE2[i] *= 0.0003141592;			\
+    dst##TYPE1##TYPE2[i] = -1;					\
+  }                             				\
+  vfwcvt_##TYPE1##TYPE2 (dst##TYPE1##TYPE2,			\
+			src##TYPE1##TYPE2, SZ);			\
+  for (int i = 0; i < SZ; i++)					\
+    assert (__builtin_fabs (dst##TYPE1##TYPE2[i]		\
+	    - ((i & 1) ? -i : i) * 0.0003141592) < EPS);	\
+
+
+#define RUN_ALL()						\
+ RUN(_Float16, float)						\
+ RUN(_Float16, double)						\
+
+int main ()
+{
+  RUN_ALL()
+}