commit 610d604f5b4be220ea0f404af871c4365026a6a7 (tree)
parent 53dcf78a25b47aa28d271c4c520eafb7c3474704
Author: Andrew Kelley <andrew@ziglang.org>
Date: Sat, 3 Dec 2022 02:18:07 -0500
Merge pull request #13748 from jacobly0/c-unaligned
cbe: use memcpy for underaligned loads and stores
Diffstat:
9 files changed, 61 insertions(+), 34 deletions(-)
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
@@ -3017,30 +3017,31 @@ fn airArg(f: *Function) CValue {
fn airLoad(f: *Function, inst: Air.Inst.Index) !CValue {
const ty_op = f.air.instructions.items(.data)[inst].ty_op;
const ptr_info = f.air.typeOf(ty_op.operand).ptrInfo().data;
+ const src_ty = ptr_info.pointee_type;
- const inst_ty = f.air.typeOfIndex(inst);
- if (!inst_ty.hasRuntimeBitsIgnoreComptime() or
+ if (!src_ty.hasRuntimeBitsIgnoreComptime() or
!ptr_info.@"volatile" and f.liveness.isUnused(inst))
return CValue.none;
const target = f.object.dg.module.getTarget();
- const is_array = lowersToArray(inst_ty, target);
+ const is_aligned = ptr_info.@"align" == 0 or ptr_info.@"align" >= src_ty.abiAlignment(target);
+ const is_array = lowersToArray(src_ty, target);
+ const need_memcpy = !is_aligned or is_array;
const operand = try f.resolveInst(ty_op.operand);
const writer = f.object.writer();
- // We need to separately initialize arrays with a memcpy so they must be mutable.
- const local = try f.allocLocal(inst_ty, if (is_array) .Mut else .Const);
+ // We need to initialize arrays and unaligned loads with a memcpy so they must be mutable.
+ const local = try f.allocLocal(src_ty, if (need_memcpy) .Mut else .Const);
- if (is_array) {
- // Insert a memcpy to initialize this array. The source operand is always a pointer
- // and thus we only need to know size/type information from the local type/dest.
+ if (need_memcpy) {
try writer.writeAll(";\n");
try writer.writeAll("memcpy(");
+ if (!is_array) try writer.writeByte('&');
try f.writeCValue(writer, local, .FunctionArgument);
- try writer.writeAll(", ");
- try f.writeCValue(writer, operand, .FunctionArgument);
+ try writer.writeAll(", (const char *)");
+ try f.writeCValue(writer, operand, .Other);
try writer.writeAll(", sizeof(");
- try f.renderTypecast(writer, inst_ty);
+ try f.renderTypecast(writer, src_ty);
try writer.writeAll("))");
} else if (ptr_info.host_size != 0) {
var host_pl = Type.Payload.Bits{
@@ -3063,12 +3064,12 @@ fn airLoad(f: *Function, inst: Air.Inst.Index) !CValue {
var field_pl = Type.Payload.Bits{
.base = .{ .tag = .int_unsigned },
- .data = @intCast(u16, inst_ty.bitSize(target)),
+ .data = @intCast(u16, src_ty.bitSize(target)),
};
const field_ty = Type.initPayload(&field_pl.base);
try writer.writeAll(" = (");
- try f.renderTypecast(writer, inst_ty);
+ try f.renderTypecast(writer, src_ty);
try writer.writeAll(")zig_wrap_");
try f.object.dg.renderTypeForBuiltinFnName(writer, field_ty);
try writer.writeAll("((");
@@ -3244,8 +3245,13 @@ fn airStore(f: *Function, inst: Air.Inst.Index) !CValue {
return try airStoreUndefined(f, ptr_info.pointee_type, ptr_val);
const target = f.object.dg.module.getTarget();
+ const is_aligned = ptr_info.@"align" == 0 or
+ ptr_info.@"align" >= ptr_info.pointee_type.abiAlignment(target);
+ const is_array = lowersToArray(ptr_info.pointee_type, target);
+ const need_memcpy = !is_aligned or is_array;
const writer = f.object.writer();
- if (lowersToArray(ptr_info.pointee_type, target)) {
+
+ if (need_memcpy) {
// For this memcpy to safely work we need the rhs to have the same
// underlying type as the lhs (i.e. they must both be arrays of the same underlying type).
assert(src_ty.eql(ptr_info.pointee_type, f.object.dg.module));
@@ -3262,9 +3268,10 @@ fn airStore(f: *Function, inst: Air.Inst.Index) !CValue {
break :blk new_local;
} else src_val;
- try writer.writeAll("memcpy(");
+ try writer.writeAll("memcpy((char *)");
try f.writeCValue(writer, ptr_val, .FunctionArgument);
try writer.writeAll(", ");
+ if (!is_array) try writer.writeByte('&');
try f.writeCValue(writer, array_src, .FunctionArgument);
try writer.writeAll(", sizeof(");
try f.renderTypecast(writer, src_ty);
@@ -4186,11 +4193,46 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue {
extra_i += clobber.len / 4 + 1;
}
}
- const asm_source = std.mem.sliceAsBytes(f.air.extra[extra_i..])[0..extra.data.source_len];
+ {
+ const asm_source = std.mem.sliceAsBytes(f.air.extra[extra_i..])[0..extra.data.source_len];
+
+ var stack = std.heap.stackFallback(256, f.object.dg.gpa);
+ const allocator = stack.get();
+ const fixed_asm_source = try allocator.alloc(u8, asm_source.len);
+ defer allocator.free(fixed_asm_source);
+
+ var src_i: usize = 0;
+ var dst_i: usize = 0;
+ while (src_i < asm_source.len) : (src_i += 1) {
+ fixed_asm_source[dst_i] = asm_source[src_i];
+ dst_i += 1;
+ if (asm_source[src_i] != '%' or src_i + 1 >= asm_source.len) continue;
+ src_i += 1;
+ if (asm_source[src_i] != '[') {
+ // This handles %%
+ fixed_asm_source[dst_i] = asm_source[src_i];
+ dst_i += 1;
+ continue;
+ }
+ const len = std.mem.indexOfScalar(u8, asm_source[src_i + 1 ..], ']') orelse
+ return f.fail("CBE: invalid inline asm string '{s}'", .{asm_source});
+ if (std.mem.indexOfScalar(u8, asm_source[src_i + 1 ..][0..len], ':')) |colon| {
+ const modifier = asm_source[src_i + 1 + colon + 1 .. src_i + 1 + len];
+ std.mem.copy(u8, fixed_asm_source[dst_i..], modifier);
+ dst_i += modifier.len;
+
+ const name = asm_source[src_i .. src_i + 1 + colon];
+ std.mem.copy(u8, fixed_asm_source[dst_i..], name);
+ dst_i += name.len;
+
+ src_i += len;
+ }
+ }
- try writer.writeAll("__asm");
- if (is_volatile) try writer.writeAll(" volatile");
- try writer.print("({s}", .{fmtStringLiteral(asm_source)});
+ try writer.writeAll("__asm");
+ if (is_volatile) try writer.writeAll(" volatile");
+ try writer.print("({s}", .{fmtStringLiteral(fixed_asm_source[0..dst_i])});
+ }
extra_i = constraints_extra_begin;
var locals_index = locals_begin;
diff --git a/test/behavior/asm.zig b/test/behavior/asm.zig
@@ -140,7 +140,6 @@ export fn derp() i32 {
test "asm modifiers (AArch64)" {
if (builtin.target.cpu.arch != .aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
var x: u32 = 15;
const double = asm ("add %[ret:w], %[in:w], %[in:w]"
diff --git a/test/behavior/basic.zig b/test/behavior/basic.zig
@@ -754,7 +754,6 @@ fn maybe(x: bool) anyerror!?u32 {
}
test "pointer to thread local array" {
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
@@ -770,7 +769,6 @@ threadlocal var buffer: [11]u8 = undefined;
test "auto created variables have correct alignment" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
const S = struct {
fn foo(str: [*]const u8) u32 {
diff --git a/test/behavior/bitreverse.zig b/test/behavior/bitreverse.zig
@@ -155,7 +155,6 @@ fn vector0() !void {
test "bitReverse vectors u0" {
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
comptime try vector0();
diff --git a/test/behavior/byteswap.zig b/test/behavior/byteswap.zig
@@ -121,7 +121,6 @@ fn vector0() !void {
test "@byteSwap vectors u0" {
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
comptime try vector0();
diff --git a/test/behavior/math.zig b/test/behavior/math.zig
@@ -1518,7 +1518,6 @@ fn testRound(comptime T: type, x: T) !void {
}
test "vector integer addition" {
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
diff --git a/test/behavior/ptrcast.zig b/test/behavior/ptrcast.zig
@@ -78,7 +78,6 @@ fn testReinterpretBytesAsExternStruct() !void {
test "reinterpret bytes of an extern struct (with under-aligned fields) into another" {
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO: Under-aligned fields are not yet supported in the CBE
try testReinterpretExternStructAsExternStruct();
comptime try testReinterpretExternStructAsExternStruct();
diff --git a/test/behavior/struct.zig b/test/behavior/struct.zig
@@ -641,7 +641,6 @@ test "default struct initialization fields" {
test "packed array 24bits" {
if (builtin.zig_backend == .stage1) return error.SkipZigTest;
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
diff --git a/test/behavior/vector.zig b/test/behavior/vector.zig
@@ -75,7 +75,6 @@ test "vector bin compares with mem.eql" {
test "vector int operators" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -139,7 +138,6 @@ test "vector bit operators" {
test "implicit cast vector to array" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -158,7 +156,6 @@ test "implicit cast vector to array" {
test "array to vector" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -177,7 +174,6 @@ test "array to vector" {
test "tuple to vector" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -210,7 +206,6 @@ test "tuple to vector" {
test "vector casts of sizes not divisible by 8" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -945,7 +940,6 @@ test "multiplication-assignment operator with an array operand" {
return error.SkipZigTest;
}
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
@@ -1194,7 +1188,6 @@ test "zero divisor" {
test "zero multiplicand" {
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
- if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
