SVE intrinsics: Fold constant operands for svmul.

This patch implements constant folding for svmul by calling
gimple_folder::fold_const_binary with tree_code MULT_EXPR.
Tests were added to check the produced assembly for different
predicates, signed and unsigned integers, and the svmul_n_* case.

The patch was bootstrapped and regtested on aarch64-linux-gnu, no regression.
OK for mainline?

Signed-off-by: Jennifer Schmitz <jschmitz@nvidia.com>

gcc/
	* config/aarch64/aarch64-sve-builtins-base.cc (svmul_impl::fold):
	Try constant folding.

gcc/testsuite/
	* gcc.target/aarch64/sve/const_fold_mul_1.c: New test.

2 files changed, 316 insertions, 1 deletions

diff --git a/gcc/config/aarch64/aarch64-sve-builtins-base.cc b/gcc/config/aarch64/aarch64-sve-builtins-base.cc
index 6c94d14..8f781e2 100644
--- a/gcc/config/aarch64/aarch64-sve-builtins-base.cc
+++ b/gcc/config/aarch64/aarch64-sve-builtins-base.cc
@@ -2000,6 +2000,19 @@ public:
   }
 };
 
+class svmul_impl : public rtx_code_function
+{
+public:
+  CONSTEXPR svmul_impl ()
+    : rtx_code_function (MULT, MULT, UNSPEC_COND_FMUL) {}
+
+  gimple *
+  fold (gimple_folder &f) const override
+  {
+    return f.fold_const_binary (MULT_EXPR);
+  }
+};
+
 class svnand_impl : public function_base
 {
 public:
@@ -3184,7 +3197,7 @@ FUNCTION (svmls_lane, svmls_lane_impl,)
 FUNCTION (svmmla, svmmla_impl,)
 FUNCTION (svmov, svmov_impl,)
 FUNCTION (svmsb, svmsb_impl,)
-FUNCTION (svmul, rtx_code_function, (MULT, MULT, UNSPEC_COND_FMUL))
+FUNCTION (svmul, svmul_impl,)
 FUNCTION (svmul_lane, CODE_FOR_MODE0 (aarch64_mul_lane),)
 FUNCTION (svmulh, unspec_based_function, (UNSPEC_SMUL_HIGHPART,
 					  UNSPEC_UMUL_HIGHPART, -1))
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/const_fold_mul_1.c b/gcc/testsuite/gcc.target/aarch64/sve/const_fold_mul_1.c
new file mode 100644
index 0000000..6d68607
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/const_fold_mul_1.c
@@ -0,0 +1,302 @@
+/* { dg-final { check-function-bodies "**" "" } } */
+/* { dg-options "-O2" } */
+
+#include "arm_sve.h"
+
+/*
+** s64_x_pg:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_x_pg (svbool_t pg)
+{
+  return svmul_x (pg, svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_x_pg_0:
+**	mov	z[0-9]+\.b, #0
+**	ret
+*/
+svint64_t s64_x_pg_0 (svbool_t pg)
+{
+  return svmul_x (pg, svdup_s64 (0), svdup_s64 (3));
+}
+
+/*
+** s64_z_pg:
+**	mov	z[0-9]+\.d, p[0-7]/z, #15
+**	ret
+*/
+svint64_t s64_z_pg (svbool_t pg)
+{
+  return svmul_z (pg, svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_z_pg_0:
+**	mov	z[0-9]+\.d, p[0-7]/z, #0
+**	ret
+*/
+svint64_t s64_z_pg_0 (svbool_t pg)
+{
+  return svmul_z (pg, svdup_s64 (0), svdup_s64 (3));
+}
+
+/*
+** s64_m_pg:
+**	mov	(z[0-9]+\.d), #3
+**	mov	(z[0-9]+\.d), #5
+**	mul	\2, p[0-7]/m, \2, \1
+**	ret
+*/
+svint64_t s64_m_pg (svbool_t pg)
+{
+  return svmul_m (pg, svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_x_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_x_ptrue ()
+{
+  return svmul_x (svptrue_b64 (), svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_z_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_z_ptrue ()
+{
+  return svmul_z (svptrue_b64 (), svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_m_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_m_ptrue ()
+{
+  return svmul_m (svptrue_b64 (), svdup_s64 (5), svdup_s64 (3));
+}
+
+/*
+** s64_x_pg_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_x_pg_n (svbool_t pg)
+{
+  return svmul_n_s64_x (pg, svdup_s64 (5), 3);
+}
+
+/*
+** s64_x_pg_n_s64_0:
+**	mov	z[0-9]+\.b, #0
+**	ret
+*/
+svint64_t s64_x_pg_n_s64_0 (svbool_t pg)
+{
+  return svmul_n_s64_x (pg, svdup_s64 (5), 0);
+}
+
+/*
+** s64_z_pg_n:
+**	mov	z[0-9]+\.d, p[0-7]/z, #15
+**	ret
+*/
+svint64_t s64_z_pg_n (svbool_t pg)
+{
+  return svmul_n_s64_z (pg, svdup_s64 (5), 3);
+}
+
+/*
+** s64_z_pg_n_s64_0:
+**	mov	z[0-9]+\.d, p[0-7]/z, #0
+**	ret
+*/
+svint64_t s64_z_pg_n_s64_0 (svbool_t pg)
+{
+  return svmul_n_s64_z (pg, svdup_s64 (5), 0);
+}
+
+/*
+** s64_m_pg_n:
+**	mov	(z[0-9]+\.d), #3
+**	mov	(z[0-9]+\.d), #5
+**	mul	\2, p[0-7]/m, \2, \1
+**	ret
+*/
+svint64_t s64_m_pg_n (svbool_t pg)
+{
+  return svmul_n_s64_m (pg, svdup_s64 (5), 3);
+}
+
+/*
+** s64_x_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_x_ptrue_n ()
+{
+  return svmul_n_s64_x (svptrue_b64 (), svdup_s64 (5), 3);
+}
+
+/*
+** s64_z_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_z_ptrue_n ()
+{
+  return svmul_n_s64_z (svptrue_b64 (), svdup_s64 (5), 3);
+}
+
+/*
+** s64_m_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svint64_t s64_m_ptrue_n ()
+{
+  return svmul_n_s64_m (svptrue_b64 (), svdup_s64 (5), 3);
+}
+
+/*
+** u64_x_pg:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_x_pg (svbool_t pg)
+{
+  return svmul_x (pg, svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_z_pg:
+**	mov	z[0-9]+\.d, p[0-7]/z, #15
+**	ret
+*/
+svuint64_t u64_z_pg (svbool_t pg)
+{
+  return svmul_z (pg, svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_m_pg:
+**	mov	(z[0-9]+\.d), #3
+**	mov	(z[0-9]+\.d), #5
+**	mul	\2, p[0-7]/m, \2, \1
+**	ret
+*/
+svuint64_t u64_m_pg (svbool_t pg)
+{
+  return svmul_m (pg, svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_x_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_x_ptrue ()
+{
+  return svmul_x (svptrue_b64 (), svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_z_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_z_ptrue ()
+{
+  return svmul_z (svptrue_b64 (), svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_m_ptrue:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_m_ptrue ()
+{
+  return svmul_m (svptrue_b64 (), svdup_u64 (5), svdup_u64 (3));
+}
+
+/*
+** u64_x_pg_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_x_pg_n (svbool_t pg)
+{
+  return svmul_n_u64_x (pg, svdup_u64 (5), 3);
+}
+
+/*
+** u64_z_pg_n:
+**	mov	z[0-9]+\.d, p[0-7]/z, #15
+**	ret
+*/
+svuint64_t u64_z_pg_n (svbool_t pg)
+{
+  return svmul_n_u64_z (pg, svdup_u64 (5), 3);
+}
+
+/*
+** u64_m_pg_n:
+**	mov	(z[0-9]+\.d), #3
+**	mov	(z[0-9]+\.d), #5
+**	mul	\2, p[0-7]/m, \2, \1
+**	ret
+*/
+svuint64_t u64_m_pg_n (svbool_t pg)
+{
+  return svmul_n_u64_m (pg, svdup_u64 (5), 3);
+}
+
+/*
+** u64_x_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_x_ptrue_n ()
+{
+  return svmul_n_u64_x (svptrue_b64 (), svdup_u64 (5), 3);
+}
+
+/*
+** u64_z_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_z_ptrue_n ()
+{
+  return svmul_n_u64_z (svptrue_b64 (), svdup_u64 (5), 3);
+}
+
+/*
+** u64_m_ptrue_n:
+**	mov	z[0-9]+\.d, #15
+**	ret
+*/
+svuint64_t u64_m_ptrue_n ()
+{
+  return svmul_n_u64_m (svptrue_b64 (), svdup_u64 (5), 3);
+}
+
+/*
+** u32_x_pg:
+**	mov	z[0-9]+\.s, #60
+**	ret
+*/
+svuint32_t u32_x_pg (svbool_t pg)
+{
+  return svmul_x (pg, svdupq_u32 (3, 15, 1, 12), svdupq_u32 (20, 4, 60, 5));
+}