RISC-V: Implement the .SAT_TRUNC for scalar

This patch would like to implement the simple .SAT_TRUNC pattern
in the riscv backend. Aka:

Form 1:
  #define DEF_SAT_U_TRUC_FMT_1(NT, WT)     \
  NT __attribute__((noinline))             \
  sat_u_truc_##WT##_to_##NT##_fmt_1 (WT x) \
  {                                        \
    bool overflow = x > (WT)(NT)(-1);      \
    return ((NT)x) | (NT)-overflow;        \
  }

DEF_SAT_U_TRUC_FMT_1(uint32_t, uint64_t)

Before this patch:
__attribute__((noinline))
uint8_t sat_u_truc_uint16_t_to_uint8_t_fmt_1 (uint16_t x)
{
  _Bool overflow;
  unsigned char _1;
  unsigned char _2;
  unsigned char _3;
  uint8_t _6;

;;   basic block 2, loop depth 0
;;    pred:       ENTRY
  overflow_5 = x_4(D) > 255;
  _1 = (unsigned char) x_4(D);
  _2 = (unsigned char) overflow_5;
  _3 = -_2;
  _6 = _1 | _3;
  return _6;
;;    succ:       EXIT

}

After this patch:
__attribute__((noinline))
uint8_t sat_u_truc_uint16_t_to_uint8_t_fmt_1 (uint16_t x)
{
  uint8_t _6;

;;   basic block 2, loop depth 0
;;    pred:       ENTRY
  _6 = .SAT_TRUNC (x_4(D)); [tail call]
  return _6;
;;    succ:       EXIT

}

The below tests suites are passed for this patch
1. The rv64gcv fully regression test.
2. The rv64gcv build with glibc

gcc/ChangeLog:

	* config/riscv/iterators.md (ANYI_DOUBLE_TRUNC): Add new iterator
	for int double truncation.
	(ANYI_DOUBLE_TRUNCATED): Add new attr for int double truncation.
	(anyi_double_truncated): Ditto but for lowercase.
	* config/riscv/riscv-protos.h (riscv_expand_ustrunc): Add new
	func decl for expanding ustrunc
	* config/riscv/riscv.cc (riscv_expand_ustrunc): Add new func
	impl to expand ustrunc.
	* config/riscv/riscv.md (ustrunc<mode><anyi_double_truncated>2): Impl
	the new pattern ustrunc<m><n>2 for int.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/sat_arith.h: Add test helper macro.
	* gcc.target/riscv/sat_arith_data.h: New test.
	* gcc.target/riscv/sat_u_trunc-1.c: New test.
	* gcc.target/riscv/sat_u_trunc-2.c: New test.
	* gcc.target/riscv/sat_u_trunc-3.c: New test.
	* gcc.target/riscv/sat_u_trunc-run-1.c: New test.
	* gcc.target/riscv/sat_u_trunc-run-2.c: New test.
	* gcc.target/riscv/sat_u_trunc-run-3.c: New test.
	* gcc.target/riscv/scalar_sat_unary.h: New test.

Signed-off-by: Pan Li <pan2.li@intel.com>

0 files changed, 0 insertions, 0 deletions