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codegen/llvm: fix memset with vectors smaller than one byte

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The special case to take advantage of llvm's intrinsic
was generating invalid llvm ir:

```
Invalid bitcast
  %60 = bitcast <2 x i2> %59 to i8, !dbg !3122
thread 145453 panic: LLVM module verification failed
```
This commit is contained in:
Xavier Bouchoux 2023-06-22 06:51:25 +00:00 committed by Andrew Kelley
parent 71dfce31bb
commit 5ab1854602
2 changed files with 53 additions and 2 deletions
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6
src/codegen/llvm.zig
View File

@ -8637,9 +8637,11 @@ pub const FuncGen = struct {
return result_ptr;
}
if (llvm_dest_ty.isStruct(&o.builder)) {
if (llvm_dest_ty.isStruct(&o.builder) or
((operand_ty.zigTypeTag(mod) == .Vector or inst_ty.zigTypeTag(mod) == .Vector) and operand_ty.bitSize(mod) != inst_ty.bitSize(mod)))
{
// Both our operand and our result are values, not pointers,
// but LLVM won't let us bitcast struct values.
// but LLVM won't let us bitcast struct values or vectors with padding bits.
// Therefore, we store operand to alloca, then load for result.
const alignment = Builder.Alignment.fromByteUnits(
@max(operand_ty.abiAlignment(mod), inst_ty.abiAlignment(mod)),

49
test/behavior/vector.zig
View File

@ -1324,6 +1324,55 @@ test "store to vector in slice" {
try expectEqual(v[1], v[0]);
}
test "store vector with memset" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) 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_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_llvm) {
switch (builtin.target.cpu.arch) {
.wasm32,
.mips,
.mipsel,
.mips64,
.mips64el,
.riscv64,
.powerpc,
=> {
// LLVM 16 ERROR: "Converting bits to bytes lost precision"
// https://github.com/ziglang/zig/issues/16177
return error.SkipZigTest;
},
else => {},
}
}
var a: [5]@Vector(2, i1) = undefined;
var b: [5]@Vector(2, u2) = undefined;
var c: [5]@Vector(2, i4) = undefined;
var d: [5]@Vector(2, u8) = undefined;
var e: [5]@Vector(2, i9) = undefined;
var ka = @Vector(2, i1){ -1, 0 };
var kb = @Vector(2, u2){ 0, 1 };
var kc = @Vector(2, i4){ 2, 3 };
var kd = @Vector(2, u8){ 4, 5 };
var ke = @Vector(2, i9){ 6, 7 };
@memset(&a, ka);
@memset(&b, kb);
@memset(&c, kc);
@memset(&d, kd);
@memset(&e, ke);
try std.testing.expectEqual(ka, a[0]);
try std.testing.expectEqual(kb, b[1]);
try std.testing.expectEqual(kc, c[2]);
try std.testing.expectEqual(kd, d[3]);
try std.testing.expectEqual(ke, e[4]);
}
test "addition of vectors represented as strings" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO