tests/tcg/s390x: Test CLGEBR and CGEBRA

Add a small test to prevent regressions.

Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230724082032.66864-10-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/tcg/s390x/Makefile.target

@@ -39,12 +39,17 @@ TESTS+=mxdb
 TESTS+=epsw
 TESTS+=larl
 TESTS+=mdeb
+TESTS+=cgebra
+TESTS+=clgebr
 
 cdsg: CFLAGS+=-pthread
 cdsg: LDFLAGS+=-pthread
 
 rxsbg: CFLAGS+=-O2
 
+cgebra: LDFLAGS+=-lm
+clgebr: LDFLAGS+=-lm
+
 include $(S390X_SRC)/pgm-specification.mak
 $(PGM_SPECIFICATION_TESTS): pgm-specification-user.o
 $(PGM_SPECIFICATION_TESTS): LDFLAGS+=pgm-specification-user.o

tests/tcg/s390x/cgebra.c

@@ -0,0 +1,32 @@
+/*
+ * Test the CGEBRA instruction.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <fenv.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    float r2 = 1E+300;
+    long long r1;
+    int cc;
+
+    feclearexcept(FE_ALL_EXCEPT);
+    asm("cgebra %[r1],%[m3],%[r2],%[m4]\n"
+        "ipm %[cc]\n"
+        : [r1] "=r" (r1)
+        , [cc] "=r" (cc)
+        : [m3] "i" (5) /* round toward 0 */
+        , [r2] "f" (r2)
+        , [m4] "i" (8) /* bit 0 is set, but must be ignored; XxC is not set */
+        : "cc");
+    cc >>= 28;
+
+    assert(r1 == 0x7fffffffffffffffLL);
+    assert(cc == 3);
+    assert(fetestexcept(FE_ALL_EXCEPT) == (FE_INVALID | FE_INEXACT));
+
+    return EXIT_SUCCESS;
+}

tests/tcg/s390x/clgebr.c

@@ -0,0 +1,32 @@
+/*
+ * Test the CLGEBR instruction.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <assert.h>
+#include <fenv.h>
+#include <stdlib.h>
+
+int main(void)
+{
+    float r2 = -1;
+    long long r1;
+    int cc;
+
+    feclearexcept(FE_ALL_EXCEPT);
+    asm("clgebr %[r1],%[m3],%[r2],%[m4]\n"
+        "ipm %[cc]\n"
+        : [r1] "=r" (r1)
+        , [cc] "=r" (cc)
+        : [m3] "i" (5) /* round toward 0 */
+        , [r2] "f" (r2)
+        , [m4] "i" (8) /* bit 0 is set, but must be ignored; XxC is not set */
+        : "cc");
+    cc >>= 28;
+
+    assert(r1 == 0);
+    assert(cc == 3);
+    assert(fetestexcept(FE_ALL_EXCEPT) == (FE_INVALID | FE_INEXACT));
+
+    return EXIT_SUCCESS;
+}