motiejus/zig
1
Fork 0
Code Releases Activity

compiler_rt: work around LLVM optimizing __muloti4 to call itself

Browse Source 
This is a workaround for
https://github.com/llvm/llvm-project/issues/56403
This commit is contained in:
Andrew Kelley
2022-07-05 21:28:39 -07:00
parent 558ad19095
commit d8fc8d0118
2 changed files with 9 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
lib/compiler_rt/mulo.zig
View File

@@ -65,6 +65,15 @@ pub fn __mulodi4(a: i64, b: i64, overflow: *c_int) callconv(.C) i64 {
}
pub fn __muloti4(a: i128, b: i128, overflow: *c_int) callconv(.C) i128 {
switch (builtin.zig_backend) {
.stage1, .stage2_llvm => {
// Workaround for https://github.com/llvm/llvm-project/issues/56403
// When we call the genericSmall implementation instead, LLVM optimizer
// optimizes __muloti4 to a call to itself.
return muloXi4_genericFast(i128, a, b, overflow);
},
else => {},
}
if (2 * @bitSizeOf(i128) <= @bitSizeOf(usize)) {
return muloXi4_genericFast(i128, a, b, overflow);
} else {

8
test/behavior/math.zig
View File

@@ -609,14 +609,6 @@ test "128-bit multiplication" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if ((builtin.zig_backend == .stage1 or builtin.zig_backend == .stage2_llvm) and
builtin.cpu.arch == .wasm32)
{
// TODO This regressed with LLVM 14 due to the __muloti4 compiler-rt symbol
// being lowered to call itself despite having the "nobuiltin" attribute.
return error.SkipZigTest;
}
var a: i128 = 3;
var b: i128 = 2;
var c = a * b;