diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/builder.rs | 40 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/llvm_util.rs | 24 |
2 files changed, 38 insertions, 26 deletions
diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs index bd175e560c7..917d07e3c61 100644 --- a/compiler/rustc_codegen_llvm/src/builder.rs +++ b/compiler/rustc_codegen_llvm/src/builder.rs @@ -557,13 +557,25 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { let (size, signed) = ty.int_size_and_signed(self.tcx); let width = size.bits(); - if oop == OverflowOp::Sub && !signed { - // Emit sub and icmp instead of llvm.usub.with.overflow. LLVM considers these - // to be the canonical form. It will attempt to reform llvm.usub.with.overflow - // in the backend if profitable. - let sub = self.sub(lhs, rhs); - let cmp = self.icmp(IntPredicate::IntULT, lhs, rhs); - return (sub, cmp); + if !signed { + match oop { + OverflowOp::Sub => { + // Emit sub and icmp instead of llvm.usub.with.overflow. LLVM considers these + // to be the canonical form. It will attempt to reform llvm.usub.with.overflow + // in the backend if profitable. + let sub = self.sub(lhs, rhs); + let cmp = self.icmp(IntPredicate::IntULT, lhs, rhs); + return (sub, cmp); + } + OverflowOp::Add => { + // Like with sub above, using icmp is the preferred form. See + // <https://rust-lang.zulipchat.com/#narrow/channel/187780-t-compiler.2Fllvm/topic/.60uadd.2Ewith.2Eoverflow.60.20.28again.29/near/533041085> + let add = self.add(lhs, rhs); + let cmp = self.icmp(IntPredicate::IntULT, add, lhs); + return (add, cmp); + } + OverflowOp::Mul => {} + } } let oop_str = match oop { @@ -1327,15 +1339,13 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { &mut self, op: rustc_codegen_ssa::common::AtomicRmwBinOp, dst: &'ll Value, - mut src: &'ll Value, + src: &'ll Value, order: rustc_middle::ty::AtomicOrdering, + ret_ptr: bool, ) -> &'ll Value { - // The only RMW operation that LLVM supports on pointers is compare-exchange. - let requires_cast_to_int = self.val_ty(src) == self.type_ptr() - && op != rustc_codegen_ssa::common::AtomicRmwBinOp::AtomicXchg; - if requires_cast_to_int { - src = self.ptrtoint(src, self.type_isize()); - } + // FIXME: If `ret_ptr` is true and `src` is not a pointer, we *should* tell LLVM that the + // LHS is a pointer and the operation should be provenance-preserving, but LLVM does not + // currently support that (https://github.com/llvm/llvm-project/issues/120837). let mut res = unsafe { llvm::LLVMBuildAtomicRMW( self.llbuilder, @@ -1346,7 +1356,7 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { llvm::False, // SingleThreaded ) }; - if requires_cast_to_int { + if ret_ptr && self.val_ty(res) != self.type_ptr() { res = self.inttoptr(res, self.type_ptr()); } res diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs index 3b290e5a129..28d2100f478 100644 --- a/compiler/rustc_codegen_llvm/src/llvm_util.rs +++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs @@ -377,24 +377,25 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { let target_abi = sess.target.options.abi.as_ref(); let target_pointer_width = sess.target.pointer_width; let version = get_version(); + let lt_20_1_1 = version < (20, 1, 1); + let lt_21_0_0 = version < (21, 0, 0); cfg.has_reliable_f16 = match (target_arch, target_os) { - // Selection failure <https://github.com/llvm/llvm-project/issues/50374> - ("s390x", _) => false, - // LLVM crash without neon <https://github.com/llvm/llvm-project/issues/129394> (now fixed) + // LLVM crash without neon <https://github.com/llvm/llvm-project/issues/129394> (fixed in llvm20) ("aarch64", _) - if !cfg.target_features.iter().any(|f| f.as_str() == "neon") - && version < (20, 1, 1) => + if !cfg.target_features.iter().any(|f| f.as_str() == "neon") && lt_20_1_1 => { false } // Unsupported <https://github.com/llvm/llvm-project/issues/94434> ("arm64ec", _) => false, + // Selection failure <https://github.com/llvm/llvm-project/issues/50374> (fixed in llvm21) + ("s390x", _) if lt_21_0_0 => false, // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054> ("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false, // Infinite recursion <https://github.com/llvm/llvm-project/issues/97981> ("csky", _) => false, - ("hexagon", _) => false, + ("hexagon", _) if lt_21_0_0 => false, // (fixed in llvm21) ("powerpc" | "powerpc64", _) => false, ("sparc" | "sparc64", _) => false, ("wasm32" | "wasm64", _) => false, @@ -407,9 +408,10 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { cfg.has_reliable_f128 = match (target_arch, target_os) { // Unsupported <https://github.com/llvm/llvm-project/issues/94434> ("arm64ec", _) => false, - // Selection bug <https://github.com/llvm/llvm-project/issues/96432> - ("mips64" | "mips64r6", _) => false, - // Selection bug <https://github.com/llvm/llvm-project/issues/95471> + // Selection bug <https://github.com/llvm/llvm-project/issues/96432> (fixed in llvm20) + ("mips64" | "mips64r6", _) if lt_20_1_1 => false, + // Selection bug <https://github.com/llvm/llvm-project/issues/95471>. This issue is closed + // but basic math still does not work. ("nvptx64", _) => false, // Unsupported https://github.com/llvm/llvm-project/issues/121122 ("amdgpu", _) => false, @@ -419,8 +421,8 @@ fn update_target_reliable_float_cfg(sess: &Session, cfg: &mut TargetConfig) { // ABI unsupported <https://github.com/llvm/llvm-project/issues/41838> ("sparc", _) => false, // Stack alignment bug <https://github.com/llvm/llvm-project/issues/77401>. NB: tests may - // not fail if our compiler-builtins is linked. - ("x86", _) => false, + // not fail if our compiler-builtins is linked. (fixed in llvm21) + ("x86", _) if lt_21_0_0 => false, // MinGW ABI bugs <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115054> ("x86_64", "windows") if target_env == "gnu" && target_abi != "llvm" => false, // There are no known problems on other platforms, so the only requirement is that symbols |