From 87557b37c6fb112d9608bb4b6ba860f42febf188 Mon Sep 17 00:00:00 2001
From: riverbl <94326797+riverbl@users.noreply.github.com>
Date: Wed, 23 Aug 2023 20:30:03 +0100
Subject: [PATCH] Replace `@panic` with `unreachable`, add test

Replace `@panic` with `unreachable` in stage2 wasm `@divFloor` implementation

Add test for division and remainder operations for stage2 wasm
---
 src/arch/wasm/CodeGen.zig         |  4 +--
 test/behavior/stage2_wasm_div.zig | 54 +++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 test/behavior/stage2_wasm_div.zig

diff --git a/src/arch/wasm/CodeGen.zig b/src/arch/wasm/CodeGen.zig
index bad99e9f59..db6daa8c21 100644
--- a/src/arch/wasm/CodeGen.zig
+++ b/src/arch/wasm/CodeGen.zig
@@ -6429,7 +6429,7 @@ fn airDivFloor(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
         const zero = switch (wasm_bits) {
             32 => WValue{ .imm32 = 0 },
             64 => WValue{ .imm64 = 0 },
-            else => @panic("Unexpected wasm integer width"),
+            else => unreachable,
         };
 
         // tee leaves the value on the stack and stores it in a local.
@@ -6458,7 +6458,7 @@ fn airDivFloor(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
                 try func.addTag(.i64_extend_i32_u);
                 try func.addTag(.i64_sub);
             },
-            else => @panic("Unexpected wasm integer width"),
+            else => unreachable,
         }
 
         _ = try func.binOp(lhs_wasm, rhs_wasm, ty, .rem);
diff --git a/test/behavior/stage2_wasm_div.zig b/test/behavior/stage2_wasm_div.zig
new file mode 100644
index 0000000000..ed09578fab
--- /dev/null
+++ b/test/behavior/stage2_wasm_div.zig
@@ -0,0 +1,54 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const expect = std.testing.expect;
+
+test "wasm integer division" {
+    // This test is copied from int_div.zig, with additional test cases for @divFloor on floats.
+    // TODO: Remove this test once the division tests in math.zig and int_div.zig pass with the
+    // stage2 wasm backend.
+    if (builtin.zig_backend != .stage2_wasm) return error.SkipZigTest;
+
+    try testDivision();
+    try comptime testDivision();
+}
+fn testDivision() !void {
+    try expect(div(u32, 13, 3) == 4);
+    try expect(div(u64, 13, 3) == 4);
+    try expect(div(u8, 13, 3) == 4);
+
+    try expect(divFloor(i8, 5, 3) == 1);
+    try expect(divFloor(i16, -5, 3) == -2);
+    try expect(divFloor(i64, -0x80000000, -2) == 0x40000000);
+    try expect(divFloor(i32, 0, -0x80000000) == 0);
+    try expect(divFloor(i64, -0x40000001, 0x40000000) == -2);
+    try expect(divFloor(i32, -0x80000000, 1) == -0x80000000);
+    try expect(divFloor(i32, 10, 12) == 0);
+    try expect(divFloor(i32, -14, 12) == -2);
+    try expect(divFloor(i32, -2, 12) == -1);
+    try expect(divFloor(f32, 56.0, 9.0) == 6.0);
+    try expect(divFloor(f32, 1053.0, -41.0) == -26.0);
+    try expect(divFloor(f16, -43.0, 12.0) == -4.0);
+    try expect(divFloor(f64, -90.0, -9.0) == 10.0);
+
+    try expect(mod(u32, 10, 12) == 10);
+    try expect(mod(i32, 10, 12) == 10);
+    try expect(mod(i64, -14, 12) == 10);
+    try expect(mod(i16, -2, 12) == 10);
+    try expect(mod(i8, -2, 12) == 10);
+
+    try expect(rem(i32, 10, 12) == 10);
+    try expect(rem(i32, -14, 12) == -2);
+    try expect(rem(i32, -2, 12) == -2);
+}
+fn div(comptime T: type, a: T, b: T) T {
+    return a / b;
+}
+fn divFloor(comptime T: type, a: T, b: T) T {
+    return @divFloor(a, b);
+}
+fn mod(comptime T: type, a: T, b: T) T {
+    return @mod(a, b);
+}
+fn rem(comptime T: type, a: T, b: T) T {
+    return @rem(a, b);
+}