tests/tcg/s390x: Add a test for the vistr instruction

This test can be used to verify that the change in the previous
commit is indeed fixing the problem with the M3 vs. M4 field
mixup.

Message-Id: <20221012182755.1014853-4-thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/tcg/s390x/Makefile.target

@@ -25,6 +25,10 @@ TESTS+=signals-s390x
 TESTS+=branch-relative-long
 TESTS+=noexec
 
+Z13_TESTS=vistr
+$(Z13_TESTS): CFLAGS+=-march=z13 -O2
+TESTS+=$(Z13_TESTS)
+
 ifneq ($(CROSS_CC_HAS_Z14),)
 Z14_TESTS=vfminmax
 vfminmax: LDFLAGS+=-lm

tests/tcg/s390x/vistr.c

@@ -0,0 +1,45 @@
+/*
+ * Test the VECTOR ISOLATE STRING (vistr) instruction
+ */
+#include <stdint.h>
+#include <stdio.h>
+#include "vx.h"
+
+static inline void vistr(S390Vector *v1, S390Vector *v2,
+                         const uint8_t m3, const uint8_t m5)
+{
+    asm volatile("vistr %[v1], %[v2], %[m3], %[m5]\n"
+                 : [v1] "=v" (v1->v)
+                 : [v2]  "v" (v2->v)
+                 , [m3]  "i" (m3)
+                 , [m5]  "i" (m5)
+                 : "cc");
+}
+
+int main(int argc, char *argv[])
+{
+    S390Vector vd = {};
+    S390Vector vs16 = {
+        .h[0] = 0x1234, .h[1] = 0x0056, .h[2] = 0x7800, .h[3] = 0x0000,
+        .h[4] = 0x0078, .h[5] = 0x0000, .h[6] = 0x6543, .h[7] = 0x2100
+    };
+    S390Vector vs32 = {
+        .w[0] = 0x12340000, .w[1] = 0x78654300,
+        .w[2] = 0x0, .w[3] = 0x12,
+    };
+
+    vistr(&vd, &vs16, 1, 0);
+    if (vd.h[0] != 0x1234 || vd.h[1] != 0x0056 || vd.h[2] != 0x7800 ||
+        vd.h[3] || vd.h[4] || vd.h[5] || vd.h[6] || vd.h[7]) {
+        puts("ERROR: vitrh failed!");
+        return 1;
+    }
+
+    vistr(&vd, &vs32, 2, 0);
+    if (vd.w[0] != 0x12340000 || vd.w[1] != 0x78654300 || vd.w[2] || vd.w[3]) {
+        puts("ERROR: vitrf failed!");
+        return 1;
+    }
+
+    return 0;
+}