RISC-V: Add testcases for unsigned .SAT_SUB form 1 with IMM = max -1.

form 1:
T __attribute__((noinline))             \
sat_u_sub_imm##IMM##_##T##_fmt_1 (T y)  \
{                                       \
  return (T)IMM >= y ? (T)IMM - y : 0;  \
}

Passed the rv64gcv regression test.

Change-Id: Idaa1ab41f2a5785112279ea8ee2c93236457b740
Signed-off-by: Li Xu <xuli1@eswincomputing.com>
gcc/testsuite/ChangeLog:

	* gcc.target/riscv/sat_u_sub_imm-1_3.c: New test.
	* gcc.target/riscv/sat_u_sub_imm-2_3.c: New test.
	* gcc.target/riscv/sat_u_sub_imm-3_3.c: New test.
	* gcc.target/riscv/sat_u_sub_imm-4_1.c: New test.

4 files changed, 89 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-1_3.c b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-1_3.c
new file mode 100644
index 0000000..6f2a493
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-1_3.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } } */
+/* { dg-options "-march=rv64gc -mabi=lp64d -O3 -fdump-rtl-expand-details -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include "sat_arith.h"
+
+/*
+** sat_u_sub_imm254_uint8_t_fmt_1:
+** li\s+[atx][0-9]+,\s*254
+** sub\s+[atx][0-9]+,\s*[atx][0-9]+,\s*a0
+** sltu\s+[atx][0-9]+,\s*[atx][0-9]+,\s*[atx][0-9]+
+** addi\s+a0,\s*a0,\s*-1
+** and\s+a0,\s*a0,\s*[atx][0-9]+
+** andi\s+a0,\s*a0,\s*0xff
+** ret
+*/
+
+DEF_SAT_U_SUB_IMM_FMT_1(uint8_t, 254)
+
+/* { dg-final { scan-rtl-dump-times ".SAT_SUB " 2 "expand" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-2_3.c b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-2_3.c
new file mode 100644
index 0000000..ed03c18
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-2_3.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } } */
+/* { dg-options "-march=rv64gc -mabi=lp64d -O3 -fdump-rtl-expand-details -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include "sat_arith.h"
+
+/*
+** sat_u_sub_imm65534_uint16_t_fmt_1:
+** li\s+[atx][0-9]+,\s*65536
+** addi\s+[atx][0-9]+,\s*[atx][0-9]+,\s*-2
+** sub\s+[atx][0-9]+,\s*[atx][0-9]+,\s*a0
+** sltu\s+[atx][0-9]+,\s*[atx][0-9]+,\s*[atx][0-9]+
+** addi\s+a0,\s*a0,\s*-1
+** and\s+a0,\s*a0,\s*[atx][0-9]+
+** slli\s+a0,\s*a0,\s*48
+** srli\s+a0,\s*a0,\s*48
+** ret
+*/
+
+DEF_SAT_U_SUB_IMM_FMT_1(uint16_t, 65534)
+
+/* { dg-final { scan-rtl-dump-times ".SAT_SUB " 2 "expand" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-3_3.c b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-3_3.c
new file mode 100644
index 0000000..17d8e5f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-3_3.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } } */
+/* { dg-options "-march=rv64gc -mabi=lp64d -O3 -fdump-rtl-expand-details -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include "sat_arith.h"
+
+/*
+** sat_u_sub_imm4294967294_uint32_t_fmt_1:
+** li\s+[atx][0-9]+,\s*1
+** slli\s+[atx][0-9]+,\s*[atx][0-9]+,\s*32
+** addi\s+[atx][0-9]+,\s*[atx][0-9]+,\s*-2
+** slli\s+a0,\s*a0,\s*32
+** srli\s+a0,\s*a0,\s*32
+** sub\s+[atx][0-9]+,\s*[atx][0-9]+,\s*a0
+** sltu\s+[atx][0-9]+,\s*[atx][0-9]+,\s*[atx][0-9]+
+** addi\s+a0,\s*a0,\s*-1
+** and\s+a0,\s*a0,\s*[atx][0-9]+
+** sext\.w\s+a0,\s*a0
+** ret
+*/
+
+DEF_SAT_U_SUB_IMM_FMT_1(uint32_t, 4294967294)
+
+/* { dg-final { scan-rtl-dump-times ".SAT_SUB " 2 "expand" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-4_1.c b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-4_1.c
new file mode 100644
index 0000000..e649219
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/sat_u_sub_imm-4_1.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-flto" } } */
+/* { dg-options "-march=rv64gc -mabi=lp64d -O3 -fdump-rtl-expand-details -fno-schedule-insns -fno-schedule-insns2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include "sat_arith.h"
+
+/*
+** sat_u_sub_imm18446744073709551614u_uint64_t_fmt_1:
+** li\s+[atx][0-9]+,\s*-2
+** sub\s+[atx][0-9]+,\s*[atx][0-9]+,\s*a0
+** sltu\s+[atx][0-9]+,\s*[atx][0-9]+,\s*[atx][0-9]+
+** addi\s+a0,\s*a0,\s*-1
+** and\s+a0,\s*a0,\s*[atx][0-9]+
+** ret
+*/
+
+DEF_SAT_U_SUB_IMM_FMT_1(uint64_t, 18446744073709551614u)
+
+/* { dg-final { scan-rtl-dump-times ".SAT_SUB " 2 "expand" } } */