[PATCH] tests/tcg/ppc64le: Added OE/UE enabled exception test

["Lucas Mateus Castro(alqotel)" <lucas.araujo@eldorado.org.br>]

From: "Lucas Mateus Castro (alqotel)" <lucas.araujo@eldorado.org.br>

DO NOT MERGE

This patch adds a test to check if the add/sub of the intermediate
result when an overflow or underflow exception with the corresponding
enabling bit being set (i.e. OE/UE), but linux-user currently can't
disable MSR.FE0 and MSR.FE1 so it will always result in a trapping
exception, to avoid that the test should be run in a VM or use Matheus'
WIP patch in 
https://github.com/PPC64/qemu/tree/alqotel-ferst-prctl-patch

The test results were based on a Power9 machine.

Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
---
 tests/tcg/ppc64le/oe_ue_excp.c | 105 +++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 tests/tcg/ppc64le/oe_ue_excp.c

diff --git a/tests/tcg/ppc64le/oe_ue_excp.c b/tests/tcg/ppc64le/oe_ue_excp.c
new file mode 100644
index 0000000000..384219a366
--- /dev/null
+++ b/tests/tcg/ppc64le/oe_ue_excp.c
@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <float.h>
+#include <sys/prctl.h>
+
+#define FP_OE (1ull << 6)
+#define FP_UE (1ull << 5)
+
+typedef union {
+    double d;
+    long long ll;
+} ll_fp;
+
+double asm_fmul (double a, double b)
+{
+    double t;
+    asm (
+        "lfd 0, %1\n\t"
+        "lfd 1, %2\n\t"
+        "fmul 2, 0, 1\n\t"
+        "stfd 2, %0\n\t"
+        :"=m"(t)
+        :"m"(a),"m"(b)
+        );
+    return t;
+}
+
+double asm_fdiv (double a, double b)
+{
+    double t;
+    asm (
+        "lfd 0, %1\n\t"
+        "lfd 1, %2\n\t"
+        "fdiv 2, 0, 1\n\t"
+        "stfd 2, %0\n\t"
+        :"=m"(t)
+        :"m"(a),"m"(b)
+        );
+    return t;
+}
+
+int main ()
+{
+    int i, ok = 1;
+    ll_fp fpscr, t;
+
+    prctl(PR_SET_FPEXC, PR_FP_EXC_DISABLED);
+
+    fpscr.ll = FP_UE | FP_OE;
+    __builtin_mtfsf (0b11111111, fpscr.d);
+    fpscr.d = __builtin_mffs ();
+    printf("fpscr = %016llx\n", fpscr.ll);
+
+    ll_fp ch[] =
+                {
+                    { .ll = 0x1b64f1c1b0000000ull },
+                    { .ll = 0x1b64f1c1b0000001ull },
+                    { .ll = 0x1b90de3410000000ull },
+                    { .ll = 0x1b90de3410000000ull },
+                    { .ll = 0x5fcfffe4965a17e0ull },
+                    { .ll = 0x5fcfffe4965a17e0ull },
+                    { .ll = 0x2003ffffffffffffull },
+                    { .ll = 0x2003ffffffffffffull }
+                };
+
+    ll_fp a[] =
+                {
+                    { .ll = 0x00005ca8ull },
+                    { .ll = 0x0000badcull },
+                    { .ll = 0x7fdfffe816d77b00ull },
+                    { .d  = DBL_MAX }
+                };
+
+    ll_fp b[] =
+                {
+                    { .ll = 0x00001cefull },
+                    { .ll = 0x00005c70ull },
+                    { .ll = 0x7fdfffFC7F7FFF00ull },
+                    { .d  = 2.5 }
+                };
+
+    for (i = 0; i < 4; i++) {
+        t.d = asm_fmul(a[i].d, b[i].d);
+        if (t.ll != ch[2 * i].ll) {
+            ok = 0;
+            printf ("Mismatch on fmul n %d:\n\tresult:   %016llx\n\t"
+                    "expected: %016llx\n", i, t.ll, ch[2 * i].ll);
+        } else {
+            printf ("Ok on fmul n %d\n", i);
+        }
+        t.d = asm_fdiv(a[i].d, 1.0/b[i].d);
+        if (t.ll != ch[2 * i + 1].ll) {
+            ok = 0;
+            printf ("Mismatch on fdiv n %d:\n\tresult:   %016llx\n\t"
+                    "expected: %016llx\n", i, t.ll, ch[2 * i + 1].ll);
+        } else {
+            printf ("Ok on fdiv n %d\n", i);
+        }
+    }
+    fpscr.d = __builtin_mffs ();
+    printf("fpscr = %016llx\n", fpscr.ll);
+    if(!ok) {
+        return -1;
+    }
+    return 0;
+}
-- 
2.31.1