| author |  Alex Rønne Petersen <alex@alexrp.com> 2025-10-03 03:22:02+02:00 |
| committer | Alex Rønne Petersen <alex@alexrp.com> 2025-10-03 03:29:20+02:00 |
| log | 91fa2c61aacd002228c37cb651fa0a350bd7ac59 |
| tree | 75efed76fbc47b7383e2fb50137bab00f962707f |
| parent | bc4da9a90743c11c7c0b3e485f46d365d57d87b7 |
| signature |  Signed by SSH key SHA256:7B/LJ7bpR1eX8aCXSr4mtd5M45VMPKcx9zY8e95b5QM |
compiler: control the s390x backchain feature through the frame pointer option
This is a little different from how C/C++ compilers do this, but I think it's
justified because it's what users actually *mean* when the use frame pointer
options.
This is another one of those LLVM "CPU" features that have nothing to do with
CPU at all and should really be a TargetMachine option or something. One day
we'll figure out a better way of dealing with these...2 files changed, 10 insertions(+), 3 deletions(-)
src- Compilation.zig
- Package
src/Compilation.zig+6-2
| ... | ... | @@ -7193,6 +7193,9 @@ pub fn addCCArgs( |
| 7193 | 7193 | } |
| 7194 | 7194 | |
| 7195 | 7195 | try argv.append(if (mod.omit_frame_pointer) "-fomit-frame-pointer" else "-fno-omit-frame-pointer"); |
| 7196 | if (target.cpu.arch == .s390x) { | |
| 7197 | try argv.append(if (mod.omit_frame_pointer) "-mbackchain" else "-mno-backchain"); | |
| 7198 | } | |
| 7196 | 7199 | |
| 7197 | 7200 | const ssp_buf_size = mod.stack_protector; |
| 7198 | 7201 | if (ssp_buf_size != 0) { |
| ... | ... | @@ -7258,9 +7261,10 @@ pub fn addCCArgs( |
| 7258 | 7261 | const is_enabled = target.cpu.features.isEnabled(index); |
| 7259 | 7262 | |
| 7260 | 7263 | if (feature.llvm_name) |llvm_name| { |
| 7261 | // We communicate float ABI to Clang through the dedicated options. | |
| 7264 | // We communicate these to Clang through the dedicated options. | |
| 7262 | 7265 | if (std.mem.startsWith(u8, llvm_name, "soft-float") or |
| 7263 | std.mem.startsWith(u8, llvm_name, "hard-float")) | |
| 7266 | std.mem.startsWith(u8, llvm_name, "hard-float") or | |
| 7267 | (target.cpu.arch == .s390x and std.mem.eql(u8, llvm_name, "backchain"))) | |
| 7264 | 7268 | continue; |
| 7265 | 7269 | |
| 7266 | 7270 | // Ignore these until we figure out how to handle the concept of omitting features. |
src/Package/Module.zig+4-1
| ... | ... | @@ -343,7 +343,10 @@ pub fn create(arena: Allocator, options: CreateOptions) !*Package.Module { |
| 343 | 343 | // See https://github.com/ziglang/zig/issues/23539 |
| 344 | 344 | if (target_util.isDynamicAMDGCNFeature(target, feature)) continue; |
| 345 | 345 | |
| 346 | const is_enabled = target.cpu.features.isEnabled(feature.index); | |
| 346 | var is_enabled = target.cpu.features.isEnabled(feature.index); | |
| 347 | if (target.cpu.arch == .s390x and @as(std.Target.s390x.Feature, @enumFromInt(feature.index)) == .backchain) { | |
| 348 | is_enabled = !omit_frame_pointer; | |
| 349 | } | |
| 347 | 350 | |
| 348 | 351 | if (is_enabled) { |
| 349 | 352 | try buf.ensureUnusedCapacity(2 + llvm_name.len); |