Merge pull request #11223 from mparadinha/ptr-elem-val

stage2: x86_64: implement `ptr_elem_val`

3 files changed, 44 insertions, 16 deletions

diff --git a/src/arch/x86_64/CodeGen.zig b/src/arch/x86_64/CodeGen.zig
index 37d93f870c..ce049a4541 100644
--- a/src/arch/x86_64/CodeGen.zig
+++ b/src/arch/x86_64/CodeGen.zig
@@ -2174,10 +2174,44 @@ fn airArrayElemVal(self: *Self, inst: Air.Inst.Index) !void {
 fn airPtrElemVal(self: *Self, inst: Air.Inst.Index) !void {
     const is_volatile = false; // TODO
     const bin_op = self.air.instructions.items(.data)[inst].bin_op;
-    const result: MCValue = if (!is_volatile and self.liveness.isUnused(inst))
-        .dead
-    else
-        return self.fail("TODO implement ptr_elem_val for {}", .{self.target.cpu.arch});
+    const result: MCValue = if (!is_volatile and self.liveness.isUnused(inst)) .dead else result: {
+        // this is identical to the `airPtrElemPtr` codegen expect here an
+        // additional `mov` is needed at the end to get the actual value
+
+        const ptr_ty = self.air.typeOf(bin_op.lhs);
+        const ptr = try self.resolveInst(bin_op.lhs);
+        ptr.freezeIfRegister(&self.register_manager);
+        defer ptr.unfreezeIfRegister(&self.register_manager);
+
+        const elem_ty = ptr_ty.elemType2();
+        const elem_abi_size = elem_ty.abiSize(self.target.*);
+        const index_ty = self.air.typeOf(bin_op.rhs);
+        const index = try self.resolveInst(bin_op.rhs);
+        index.freezeIfRegister(&self.register_manager);
+        defer index.unfreezeIfRegister(&self.register_manager);
+
+        const offset_reg = try self.elemOffset(index_ty, index, elem_abi_size);
+        self.register_manager.freezeRegs(&.{offset_reg});
+        defer self.register_manager.unfreezeRegs(&.{offset_reg});
+
+        const dst_mcv = try self.copyToRegisterWithInstTracking(inst, ptr_ty, ptr);
+        try self.genBinMathOpMir(.add, ptr_ty, dst_mcv, .{ .register = offset_reg });
+        if (elem_abi_size > 8) {
+            return self.fail("TODO copy value with size {} from pointer", .{elem_abi_size});
+        } else {
+            // mov dst_mcv, [dst_mcv]
+            _ = try self.addInst(.{
+                .tag = .mov,
+                .ops = (Mir.Ops{
+                    .flags = 0b01,
+                    .reg1 = registerAlias(dst_mcv.register, @intCast(u32, elem_abi_size)),
+                    .reg2 = dst_mcv.register,
+                }).encode(),
+                .data = .{ .imm = 0 },
+            });
+            break :result .{ .register = registerAlias(dst_mcv.register, @intCast(u32, elem_abi_size)) };
+        }
+    };
     return self.finishAir(inst, result, .{ bin_op.lhs, bin_op.rhs, .none });
 }
 
@@ -5166,7 +5200,7 @@ fn genSetReg(self: *Self, ty: Type, reg: Register, mcv: MCValue) InnerError!void
             if (!self.wantSafety())
                 return; // The already existing value will do just fine.
             // Write the debug undefined value.
-            switch (reg.size()) {
+            switch (registerAlias(reg, abi_size).size()) {
                 8 => return self.genSetReg(ty, reg, .{ .immediate = 0xaa }),
                 16 => return self.genSetReg(ty, reg, .{ .immediate = 0xaaaa }),
                 32 => return self.genSetReg(ty, reg, .{ .immediate = 0xaaaaaaaa }),
@@ -5303,7 +5337,7 @@ fn genSetReg(self: *Self, ty: Type, reg: Register, mcv: MCValue) InnerError!void
             _ = try self.addInst(.{
                 .tag = .mov,
                 .ops = (Mir.Ops{
-                    .reg1 = reg.to64(),
+                    .reg1 = registerAlias(reg, abi_size),
                     .reg2 = reg.to64(),
                     .flags = 0b01,
                 }).encode(),
@@ -5316,7 +5350,7 @@ fn genSetReg(self: *Self, ty: Type, reg: Register, mcv: MCValue) InnerError!void
                 _ = try self.addInst(.{
                     .tag = .mov,
                     .ops = (Mir.Ops{
-                        .reg1 = reg,
+                        .reg1 = registerAlias(reg, abi_size),
                         .flags = 0b01,
                     }).encode(),
                     .data = .{ .imm = @truncate(u32, x) },
@@ -5343,8 +5377,8 @@ fn genSetReg(self: *Self, ty: Type, reg: Register, mcv: MCValue) InnerError!void
                     _ = try self.addInst(.{
                         .tag = .mov,
                         .ops = (Mir.Ops{
-                            .reg1 = reg,
-                            .reg2 = reg,
+                            .reg1 = registerAlias(reg, abi_size),
+                            .reg2 = reg.to64(),
                             .flags = 0b01,
                         }).encode(),
                         .data = .{ .imm = 0 },
diff --git a/test/behavior/basic.zig b/test/behavior/basic.zig
index bee68d675c..9931c10f9a 100644
--- a/test/behavior/basic.zig
+++ b/test/behavior/basic.zig
@@ -382,7 +382,6 @@ fn hereIsAnOpaqueType(ptr: *OpaqueA) *OpaqueA {
 test "take address of parameter" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
 
     try testTakeAddressOfParameter(12.34);
 }
@@ -408,7 +407,6 @@ fn testPointerToVoidReturnType2() *const void {
 test "array 2D const double ptr" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
 
     const rect_2d_vertexes = [_][1]f32{
@@ -421,7 +419,6 @@ test "array 2D const double ptr" {
 test "array 2D const double ptr with offset" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
 
     const rect_2d_vertexes = [_][2]f32{
@@ -434,7 +431,6 @@ test "array 2D const double ptr with offset" {
 test "array 3D const double ptr with offset" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
 
     const rect_3d_vertexes = [_][2][2]f32{
@@ -519,7 +515,6 @@ var global_foo: *i32 = undefined;
 test "peer result location with typed parent, runtime condition, comptime prongs" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
 
     const S = struct {
         fn doTheTest(arg: i32) i32 {
@@ -620,7 +615,6 @@ test "self reference through fn ptr field" {
 test "global variable initialized to global variable array element" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
 
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
 
@@ -655,7 +649,6 @@ test "global constant is loaded with a runtime-known index" {
 test "multiline string literal is null terminated" {
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
 
     const s1 =
         \\one
diff --git a/test/behavior/eval.zig b/test/behavior/eval.zig
index c02bb9daa9..cce78b1944 100644
--- a/test/behavior/eval.zig
+++ b/test/behavior/eval.zig
@@ -424,6 +424,7 @@ test "f64 at compile time is lossy" {
 }
 
 test {
+    if (builtin.zig_backend != .stage1 and builtin.os.tag == .macos) return error.SkipZigTest;
     comptime try expect(@as(f128, 1 << 113) == 10384593717069655257060992658440192);
 }