From 27dca7419e3b5f8df2fdb9aae45481aea6754bc7 Mon Sep 17 00:00:00 2001
From: Jacob Lifshay <programmerjake@gmail.com>
Date: Thu, 14 Jul 2022 02:21:54 -0700
Subject: [PATCH] add jit_test for testing icbi and isync

TODO: integrate into unit test framework
---
 .gitignore   |  2 ++
 jit_test.cpp | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 jit_test.sh  | 14 +++++++++++
 3 files changed, 85 insertions(+)
 create mode 100644 jit_test.cpp
 create mode 100755 jit_test.sh

diff --git a/.gitignore b/.gitignore
index 9b0bf1dd..40029618 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,5 @@ dist
 *.vcd
 *.gtkw
 *.egg-info
+/jit_test
+/jit_test.o
diff --git a/jit_test.cpp b/jit_test.cpp
new file mode 100644
index 00000000..78d3b5ab
--- /dev/null
+++ b/jit_test.cpp
@@ -0,0 +1,69 @@
+typedef __UINT8_TYPE__ uint8_t;
+typedef __UINT16_TYPE__ uint16_t;
+typedef __UINT32_TYPE__ uint32_t;
+typedef __UINT64_TYPE__ uint64_t;
+typedef __INT8_TYPE__ int8_t;
+typedef __INT16_TYPE__ int16_t;
+typedef __INT32_TYPE__ int32_t;
+typedef __INT64_TYPE__ int64_t;
+
+/// returns `v + inc` by jitting an addi instruction and executing it
+/// requires .wtext section to be writable
+extern "C" uint64_t jit_test(uint64_t v, int16_t inc) __attribute__((noinline, section(".wtext")));
+extern "C" uint64_t jit_test(uint64_t v, int16_t inc) {
+    register uint64_t r3 asm("r3");
+    r3 = v;
+    uint32_t instr = 0x38630000 | (uint16_t)inc; // addi 3, 3, inc
+    asm("mflr 5\n\t"
+        "bl 0f\n\t"
+        "0: mflr 4\n\t"
+        "addi 4, 4, 1f - 0b\n\t"
+        "stw %1, 0(4)\n\t"
+        "dcbf 0, 4\n\t"
+        "sync\n\t"
+        "icbi 0, 4\n\t"
+        "isync\n\t"
+        "1: addi 3, 3, 0x1234\n\t"
+        "mtlr 5"
+        : "+b"(r3) : "b"(instr) : "r4", "r5");
+    return r3;
+}
+
+extern "C" uint64_t parse_hex(const char *s) __attribute__((noinline));
+extern "C" uint64_t parse_hex(const char *s) {
+    uint64_t retval = 0;
+    bool negate = *s == '-';
+    if(*s == '-' || *s == '+')
+        s++;
+    if(*s == '0' && (s[1] == 'x' || s[1] == 'X'))
+        s += 2;
+    if(!*s)
+        return -1;
+    for(; *s; s++) {
+        uint64_t digit;
+        if(*s >= '0' && *s <= '9')
+            digit = *s - '0';
+        else if(*s >= 'a' && *s <= 'f')
+            digit = *s - 'a' + 0xA;
+        else if(*s >= 'A' && *s <= 'F')
+            digit = *s - 'A' + 0xA;
+        else
+            return -1;
+        if(retval >= 1ULL << 60)
+            return -1;
+        retval <<= 4;
+        retval += digit;
+    }
+    return retval;
+}
+
+extern "C" int main(int argc, char **argv) {
+    uint64_t a = 1, b = 2;
+    if(argc > 1)
+        a = parse_hex(argv[1]);
+    if(argc > 2)
+        b = parse_hex(argv[2]);
+    register long r3 asm("r3") = jit_test(a, b);
+    register long r0 asm("r0") = 1; // exit
+    asm volatile("sc" : : "r"(r0), "b"(r3));
+}
diff --git a/jit_test.sh b/jit_test.sh
new file mode 100755
index 00000000..c32ce1cb
--- /dev/null
+++ b/jit_test.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+set -xe
+clang --target=powerpc64le-linux-gnu -Og -g -c -o jit_test.o jit_test.cpp
+powerpc64le-linux-gnu-objcopy --set-section-flags .wtext=CONTENTS,ALLOC,LOAD,CODE jit_test.o
+powerpc64le-linux-gnu-gcc -static -o jit_test jit_test.o
+set +e
+for i in {-3..3}; do
+    printf -v ih "%#x" "$i"
+    for j in {-3..3}; do
+        printf -v jh "%#x" "$j"
+        ./jit_test "$ih" "$jh"
+        echo "return value $? -- should be $(((i + j) & 0xFF))"
+    done
+done
-- 
2.30.2