From cd6888677ebee6f8b37310da28a5e2b373933c3d Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 23 Apr 2021 19:53:57 +0100
Subject: [PATCH] add branch test cases

---
 src/openpower/test/branch/branch_cases.py | 94 +++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 src/openpower/test/branch/branch_cases.py

diff --git a/src/openpower/test/branch/branch_cases.py b/src/openpower/test/branch/branch_cases.py
new file mode 100644
index 00000000..40a2452a
--- /dev/null
+++ b/src/openpower/test/branch/branch_cases.py
@@ -0,0 +1,94 @@
+from openpower.decoder.isa.caller import special_sprs
+from openpower.decoder.selectable_int import SelectableInt
+from openpower.simulator.program import Program
+from openpower.endian import bigendian
+
+from openpower.test.common import TestAccumulatorBase
+import random
+
+
+class BranchTestCase(TestAccumulatorBase):
+
+    def case_0_regression_unconditional(self):
+        for i in range(2):
+            imm = random.randrange(-1 << 23, (1 << 23)-1) * 4
+            lst = [f"bl {imm}"]
+            initial_regs = [0] * 32
+            self.add_case(Program(lst, bigendian), initial_regs)
+
+    def case_unconditional(self):
+        choices = ["b", "ba", "bl", "bla"]
+        for i in range(20):
+            choice = random.choice(choices)
+            imm = random.randrange(-1 << 23, (1 << 23)-1) * 4
+            lst = [f"{choice} {imm}"]
+            initial_regs = [0] * 32
+            self.add_case(Program(lst, bigendian), initial_regs)
+
+    def case_bc_cr(self):
+        for i in range(20):
+            bc = random.randrange(-1 << 13, (1 << 13)-1) * 4
+            bo = random.choice([0b01100, 0b00100, 0b10100])
+            bi = random.randrange(0, 31)
+            cr = random.randrange(0, (1 << 32)-1)
+            lst = [f"bc {bo}, {bi}, {bc}"]
+            initial_regs = [0] * 32
+            self.add_case(Program(lst, bigendian), initial_cr=cr)
+
+    def case_bc_ctr(self):
+        for i in range(20):
+            bc = random.randrange(-1 << 13, (1 << 13)-1) * 4
+            bo = random.choice([0, 2, 8, 10, 16, 18])
+            bi = random.randrange(0, 31)
+            cr = random.randrange(0, (1 << 32)-1)
+            ctr = random.randint(0, (1 << 32)-1)
+            lst = [f"bc {bo}, {bi}, {bc}"]
+            initial_sprs = {9: SelectableInt(ctr, 64)}
+            self.add_case(Program(lst, bigendian),
+                          initial_sprs=initial_sprs,
+                          initial_cr=cr)
+
+    def case_bc_reg(self):
+        # XXX: bcctr and bcctrl time out (irony: they're counters)
+        choices = ["bclr", "bclrl", "bcctr", "bcctrl", "bctar", "bctarl"]
+        for insn in choices:
+            for i in range(20):
+                bh = random.randrange(0, 3)
+                bo = random.choice([4, 12])
+                bi = random.randrange(0, 31)
+                cr = random.randrange(0, (1 << 32)-1)
+                ctr = random.randint(0, (1 << 32)-1)
+                lr = random.randint(0, (1 << 64)-1) & ~3
+                tar = random.randint(0, (1 << 64)-1) & ~3
+                lst = [f"{insn} {bo}, {bi}, {bh}"]
+                initial_sprs = {9: SelectableInt(ctr, 64),
+                                8: SelectableInt(lr, 64),
+                                815: SelectableInt(tar, 64)}
+                self.add_case(Program(lst, bigendian),
+                              initial_sprs=initial_sprs,
+                              initial_cr=cr)
+
+    def case_bc_microwatt_1_regression(self):
+        """bc found to be testing ctr rather than (ctr-1)
+        11fb4:   08 00 49 40     bc      2,4*cr2+gt,0x11fbc
+        cr_file.vhdl:83:13:@136835ns:(report note): Reading CR 33209703
+        """
+        lst = ["bc 2, 9, 8"]
+        initial_regs = [0] * 32
+        cr = 0x33209703
+        self.add_case(Program(lst, bigendian), initial_regs,
+                              initial_cr=cr)
+
+    def case_bc_microwatt_2_regression(self):
+        """modified version, set CTR=1 so that it hits zero in BC
+        """
+        lst = ["bc 2, 9, 8"]
+        initial_regs = [0] * 32
+        cr = 0x33209703
+        ctr = 1
+        initial_sprs = {9: SelectableInt(ctr, 64),
+                        }
+        self.add_case(Program(lst, bigendian), initial_regs,
+                              initial_sprs=initial_sprs,
+                              initial_cr=cr)
+
-- 
2.30.2