tests/tcg/riscv64: Add test for division

Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210823195529.560295-3-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

tests/tcg/riscv64/Makefile.target

@@ -0,0 +1,5 @@
+# -*- Mode: makefile -*-
+# RISC-V specific tweaks
+
+VPATH += $(SRC_PATH)/tests/tcg/riscv64
+TESTS += test-div

tests/tcg/riscv64/test-div.c

@@ -0,0 +1,58 @@
+#include <assert.h>
+#include <limits.h>
+
+struct TestS {
+    long x, y, q, r;
+};
+
+static struct TestS test_s[] = {
+    { 4, 2, 2, 0 },                 /* normal cases */
+    { 9, 7, 1, 2 },
+    { 0, 0, -1, 0 },                /* div by zero cases */
+    { 9, 0, -1, 9 },
+    { LONG_MIN, -1, LONG_MIN, 0 },  /* overflow case */
+};
+
+struct TestU {
+    unsigned long x, y, q, r;
+};
+
+static struct TestU test_u[] = {
+    { 4, 2, 2, 0 },                 /* normal cases */
+    { 9, 7, 1, 2 },
+    { 0, 0, ULONG_MAX, 0 },         /* div by zero cases */
+    { 9, 0, ULONG_MAX, 9 },
+};
+
+#define ARRAY_SIZE(X)  (sizeof(X) / sizeof(*(X)))
+
+int main (void)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(test_s); i++) {
+        long q, r;
+
+        asm("div %0, %2, %3\n\t"
+            "rem %1, %2, %3"
+            : "=&r" (q), "=r" (r)
+            : "r" (test_s[i].x), "r" (test_s[i].y));
+
+        assert(q == test_s[i].q);
+        assert(r == test_s[i].r);
+    }
+
+    for (i = 0; i < ARRAY_SIZE(test_u); i++) {
+        unsigned long q, r;
+
+        asm("divu %0, %2, %3\n\t"
+            "remu %1, %2, %3"
+            : "=&r" (q), "=r" (r)
+            : "r" (test_u[i].x), "r" (test_u[i].y));
+
+        assert(q == test_u[i].q);
+        assert(r == test_u[i].r);
+    }
+
+    return 0;
+}