Rollup merge of #130487 - cuviper:min-llvm-18, r=nikic

Update the minimum external LLVM to 18

With this change, we'll have stable support for LLVM 18 and 19.
For reference, the previous increase to LLVM 17 was #122649.

cc `@rust-lang/wg-llvm`
r? nikic

compiler/rustc_codegen_llvm/src/abi.rs

@@ -465,9 +465,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
                     cx.type_array(cx.type_i8(), self.ret.layout.size.bytes()),
                 );
                 attributes::apply_to_llfn(llfn, llvm::AttributePlace::Argument(i), &[sret]);
-                if cx.sess().opts.optimize != config::OptLevel::No
-                    && llvm_util::get_version() >= (18, 0, 0)
-                {
+                if cx.sess().opts.optimize != config::OptLevel::No {
                     attributes::apply_to_llfn(
                         llfn,
                         llvm::AttributePlace::Argument(i),

compiler/rustc_codegen_llvm/src/builder.rs

@@ -26,13 +26,13 @@ use smallvec::SmallVec;
 use tracing::{debug, instrument};
 
 use crate::abi::FnAbiLlvmExt;
+use crate::attributes;
 use crate::common::Funclet;
 use crate::context::CodegenCx;
 use crate::llvm::{self, AtomicOrdering, AtomicRmwBinOp, BasicBlock, False, True};
 use crate::type_::Type;
 use crate::type_of::LayoutLlvmExt;
 use crate::value::Value;
-use crate::{attributes, llvm_util};
 
 // All Builders must have an llfn associated with them
 #[must_use]
@@ -1311,15 +1311,9 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
     }
 
     fn apply_attrs_to_cleanup_callsite(&mut self, llret: &'ll Value) {
-        if llvm_util::get_version() < (17, 0, 2) {
-            // Work around https://github.com/llvm/llvm-project/issues/66984.
-            let noinline = llvm::AttributeKind::NoInline.create_attr(self.llcx);
-            attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &[noinline]);
-        } else {
-            // Cleanup is always the cold path.
-            let cold_inline = llvm::AttributeKind::Cold.create_attr(self.llcx);
-            attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &[cold_inline]);
-        }
+        // Cleanup is always the cold path.
+        let cold_inline = llvm::AttributeKind::Cold.create_attr(self.llcx);
+        attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &[cold_inline]);
     }
 }
 
@@ -1761,8 +1755,6 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
     ) {
         debug!("mcdc_parameters() with args ({:?}, {:?}, {:?})", fn_name, hash, bitmap_bytes);
 
-        assert!(llvm_util::get_version() >= (18, 0, 0), "MCDC intrinsics require LLVM 18 or later");
-
         let llfn = unsafe { llvm::LLVMRustGetInstrProfMCDCParametersIntrinsic(self.cx().llmod) };
         let llty = self.cx.type_func(
             &[self.cx.type_ptr(), self.cx.type_i64(), self.cx.type_i32()],
@@ -1796,7 +1788,6 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
             "mcdc_tvbitmap_update() with args ({:?}, {:?}, {:?}, {:?}, {:?})",
             fn_name, hash, bitmap_bytes, bitmap_index, mcdc_temp
         );
-        assert!(llvm_util::get_version() >= (18, 0, 0), "MCDC intrinsics require LLVM 18 or later");
 
         let llfn =
             unsafe { llvm::LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(self.cx().llmod) };
@@ -1838,7 +1829,6 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
             "mcdc_condbitmap_update() with args ({:?}, {:?}, {:?}, {:?}, {:?})",
             fn_name, hash, cond_loc, mcdc_temp, bool_value
         );
-        assert!(llvm_util::get_version() >= (18, 0, 0), "MCDC intrinsics require LLVM 18 or later");
         let llfn = unsafe { llvm::LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(self.cx().llmod) };
         let llty = self.cx.type_func(
             &[

compiler/rustc_codegen_llvm/src/context.rs

@@ -120,14 +120,6 @@ pub(crate) unsafe fn create_module<'ll>(
 
     let mut target_data_layout = sess.target.data_layout.to_string();
     let llvm_version = llvm_util::get_version();
-    if llvm_version < (18, 0, 0) {
-        if sess.target.arch == "x86" || sess.target.arch == "x86_64" {
-            // LLVM 18 adjusts i128 to be 128-bit aligned on x86 variants.
-            // Earlier LLVMs leave this as default alignment, so remove it.
-            // See https://reviews.llvm.org/D86310
-            target_data_layout = target_data_layout.replace("-i128:128", "");
-        }
-    }
 
     if llvm_version < (19, 0, 0) {
         if sess.target.arch == "aarch64" || sess.target.arch.starts_with("arm64") {

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -258,28 +258,14 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         ("aarch64", "fhm") => Some(LLVMFeature::new("fp16fml")),
         ("aarch64", "fp16") => Some(LLVMFeature::new("fullfp16")),
         // Filter out features that are not supported by the current LLVM version
-        ("aarch64", "faminmax") if get_version().0 < 18 => None,
-        ("aarch64", "fp8") if get_version().0 < 18 => None,
-        ("aarch64", "fp8dot2") if get_version().0 < 18 => None,
-        ("aarch64", "fp8dot4") if get_version().0 < 18 => None,
-        ("aarch64", "fp8fma") if get_version().0 < 18 => None,
         ("aarch64", "fpmr") if get_version().0 != 18 => None,
-        ("aarch64", "lut") if get_version().0 < 18 => None,
-        ("aarch64", "sme-f8f16") if get_version().0 < 18 => None,
-        ("aarch64", "sme-f8f32") if get_version().0 < 18 => None,
-        ("aarch64", "sme-fa64") if get_version().0 < 18 => None,
-        ("aarch64", "sme-lutv2") if get_version().0 < 18 => None,
-        ("aarch64", "ssve-fp8dot2") if get_version().0 < 18 => None,
-        ("aarch64", "ssve-fp8dot4") if get_version().0 < 18 => None,
-        ("aarch64", "ssve-fp8fma") if get_version().0 < 18 => None,
-        ("aarch64", "v9.5a") if get_version().0 < 18 => None,
         // In LLVM 18, `unaligned-scalar-mem` was merged with `unaligned-vector-mem` into a single feature called
         // `fast-unaligned-access`. In LLVM 19, it was split back out.
         ("riscv32" | "riscv64", "unaligned-scalar-mem") if get_version().0 == 18 => {
             Some(LLVMFeature::new("fast-unaligned-access"))
         }
-        // For LLVM 18, enable the evex512 target feature if a avx512 target feature is enabled.
-        ("x86", s) if get_version().0 >= 18 && s.starts_with("avx512") => {
+        // Enable the evex512 target feature if an avx512 target feature is enabled.
+        ("x86", s) if s.starts_with("avx512") => {
             Some(LLVMFeature::with_dependency(s, TargetFeatureFoldStrength::EnableOnly("evex512")))
         }
         (_, s) => Some(LLVMFeature::new(s)),
@@ -587,7 +573,6 @@ pub(crate) fn global_llvm_features(
     // -Ctarget-features
     if !only_base_features {
         let supported_features = sess.target.supported_target_features();
-        let (llvm_major, _, _) = get_version();
         let mut featsmap = FxHashMap::default();
 
         // insert implied features
@@ -664,12 +649,6 @@ pub(crate) fn global_llvm_features(
                     return None;
                 }
 
-                // if the target-feature is "backchain" and LLVM version is greater than 18
-                // then we also need to add "+backchain" to the target-features attribute.
-                // otherwise, we will only add the naked `backchain` attribute to the attribute-group.
-                if feature == "backchain" && llvm_major < 18 {
-                    return None;
-                }
                 // ... otherwise though we run through `to_llvm_features` when
                 // passing requests down to LLVM. This means that all in-language
                 // features also work on the command line instead of having two

compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp

@@ -196,14 +196,10 @@ extern "C" LLVMRustResult LLVMRustWriteArchive(
     }
   }
 
-#if LLVM_VERSION_LT(18, 0)
-  auto Result = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
-#else
   auto SymtabMode = WriteSymbtab ? SymtabWritingMode::NormalSymtab
                                  : SymtabWritingMode::NoSymtab;
   auto Result =
       writeArchive(Dst, Members, SymtabMode, Kind, true, false, nullptr, isEC);
-#endif
   if (!Result)
     return LLVMRustResult::Success;
   LLVMRustSetLastError(toString(std::move(Result)).c_str());

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -58,17 +58,10 @@ fromRust(LLVMRustCounterMappingRegionKind Kind) {
     return coverage::CounterMappingRegion::GapRegion;
   case LLVMRustCounterMappingRegionKind::BranchRegion:
     return coverage::CounterMappingRegion::BranchRegion;
-#if LLVM_VERSION_GE(18, 0)
   case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
     return coverage::CounterMappingRegion::MCDCDecisionRegion;
   case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
     return coverage::CounterMappingRegion::MCDCBranchRegion;
-#else
-  case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
-    break;
-  case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
-    break;
-#endif
   }
   report_fatal_error("Bad LLVMRustCounterMappingRegionKind!");
 }
@@ -100,7 +93,7 @@ struct LLVMRustMCDCParameters {
 // https://github.com/rust-lang/llvm-project/blob/66a2881a/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L253-L263
 // and representations in 19
 // https://github.com/llvm/llvm-project/blob/843cc474faefad1d639f4c44c1cf3ad7dbda76c8/llvm/include/llvm/ProfileData/Coverage/MCDCTypes.h
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
 static coverage::CounterMappingRegion::MCDCParameters
 fromRust(LLVMRustMCDCParameters Params) {
   auto parameter = coverage::CounterMappingRegion::MCDCParameters{};
@@ -126,7 +119,7 @@ fromRust(LLVMRustMCDCParameters Params) {
   }
   report_fatal_error("Bad LLVMRustMCDCParametersTag!");
 }
-#elif LLVM_VERSION_GE(19, 0)
+#else
 static coverage::mcdc::Parameters fromRust(LLVMRustMCDCParameters Params) {
   switch (Params.Tag) {
   case LLVMRustMCDCParametersTag::None:
@@ -221,7 +214,7 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
            RustMappingRegions, NumMappingRegions)) {
     MappingRegions.emplace_back(
         fromRust(Region.Count), fromRust(Region.FalseCount),
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
         // LLVM 19 may move this argument to last.
         fromRust(Region.MCDCParameters),
 #endif

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -26,21 +26,19 @@
 #include "llvm/Passes/StandardInstrumentations.h"
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/TargetParser/Host.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
 #include "llvm/Transforms/IPO/Internalize.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"
 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
-#include "llvm/Transforms/Utils/AddDiscriminators.h"
-#include "llvm/Transforms/Utils/FunctionImportUtils.h"
-#if LLVM_VERSION_GE(18, 0)
-#include "llvm/TargetParser/Host.h"
-#endif
-#include "llvm/Support/TimeProfiler.h"
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/DataFlowSanitizer.h"
+#include "llvm/Transforms/Utils/AddDiscriminators.h"
+#include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #if LLVM_VERSION_GE(19, 0)
 #include "llvm/Support/PGOOptions.h"
 #endif
@@ -240,11 +238,7 @@ enum class LLVMRustCodeGenOptLevel {
   Aggressive,
 };
 
-#if LLVM_VERSION_GE(18, 0)
 using CodeGenOptLevelEnum = llvm::CodeGenOptLevel;
-#else
-using CodeGenOptLevelEnum = llvm::CodeGenOpt::Level;
-#endif
 
 static CodeGenOptLevelEnum fromRust(LLVMRustCodeGenOptLevel Level) {
   switch (Level) {
@@ -370,29 +364,23 @@ extern "C" void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef TM,
 }
 
 extern "C" size_t LLVMRustGetTargetFeaturesCount(LLVMTargetMachineRef TM) {
-#if LLVM_VERSION_GE(18, 0)
   const TargetMachine *Target = unwrap(TM);
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
       MCInfo->getAllProcessorFeatures();
   return FeatTable.size();
-#else
-  return 0;
-#endif
 }
 
 extern "C" void LLVMRustGetTargetFeature(LLVMTargetMachineRef TM, size_t Index,
                                          const char **Feature,
                                          const char **Desc) {
-#if LLVM_VERSION_GE(18, 0)
   const TargetMachine *Target = unwrap(TM);
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
       MCInfo->getAllProcessorFeatures();
   const SubtargetFeatureKV Feat = FeatTable[Index];
   *Feature = Feat.Key;
   *Desc = Feat.Desc;
-#endif
 }
 
 extern "C" const char *LLVMRustGetHostCPUName(size_t *len) {
@@ -569,17 +557,9 @@ enum class LLVMRustFileType {
 static CodeGenFileType fromRust(LLVMRustFileType Type) {
   switch (Type) {
   case LLVMRustFileType::AssemblyFile:
-#if LLVM_VERSION_GE(18, 0)
     return CodeGenFileType::AssemblyFile;
-#else
-    return CGFT_AssemblyFile;
-#endif
   case LLVMRustFileType::ObjectFile:
-#if LLVM_VERSION_GE(18, 0)
     return CodeGenFileType::ObjectFile;
-#else
-    return CGFT_ObjectFile;
-#endif
   default:
     report_fatal_error("Bad FileType.");
   }
@@ -865,11 +845,7 @@ extern "C" LLVMRustResult LLVMRustOptimize(
           // cargo run tests in multhreading mode by default
           // so use atomics for coverage counters
           Options.Atomic = true;
-#if LLVM_VERSION_GE(18, 0)
           MPM.addPass(InstrProfilingLoweringPass(Options, false));
-#else
-          MPM.addPass(InstrProfiling(Options, false));
-#endif
         });
   }
 
@@ -1210,19 +1186,13 @@ struct LLVMRustThinLTOData {
 
   // Not 100% sure what these are, but they impact what's internalized and
   // what's inlined across modules, I believe.
-#if LLVM_VERSION_GE(18, 0)
 #if LLVM_VERSION_GE(20, 0)
   FunctionImporter::ImportListsTy ImportLists;
 #else
   DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists;
 #endif
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists;
   DenseMap<StringRef, GVSummaryMapTy> ModuleToDefinedGVSummaries;
-#else
-  StringMap<FunctionImporter::ImportMapTy> ImportLists;
-  StringMap<FunctionImporter::ExportSetTy> ExportLists;
-  StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries;
-#endif
   StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
 
   LLVMRustThinLTOData() : Index(/* HaveGVs = */ false) {}
@@ -1274,11 +1244,7 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules, int num_modules,
 
     Ret->ModuleMap[module->identifier] = mem_buffer;
 
-#if LLVM_VERSION_GE(18, 0)
     if (Error Err = readModuleSummaryIndex(mem_buffer, Ret->Index)) {
-#else
-    if (Error Err = readModuleSummaryIndex(mem_buffer, Ret->Index, i)) {
-#endif
       LLVMRustSetLastError(toString(std::move(Err)).c_str());
       return nullptr;
     }

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -310,16 +310,10 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) {
     return Attribute::SafeStack;
   case FnRetThunkExtern:
     return Attribute::FnRetThunkExtern;
-#if LLVM_VERSION_GE(18, 0)
   case Writable:
     return Attribute::Writable;
   case DeadOnUnwind:
     return Attribute::DeadOnUnwind;
-#else
-  case Writable:
-  case DeadOnUnwind:
-    report_fatal_error("Not supported on this LLVM version");
-#endif
   }
   report_fatal_error("bad AttributeKind");
 }
@@ -1061,11 +1055,7 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateStaticMemberType(
   return wrap(Builder->createStaticMemberType(
       unwrapDI<DIDescriptor>(Scope), StringRef(Name, NameLen),
       unwrapDI<DIFile>(File), LineNo, unwrapDI<DIType>(Ty), fromRust(Flags),
-      unwrap<llvm::ConstantInt>(val),
-#if LLVM_VERSION_GE(18, 0)
-      llvm::dwarf::DW_TAG_member,
-#endif
-      AlignInBits));
+      unwrap<llvm::ConstantInt>(val), llvm::dwarf::DW_TAG_member, AlignInBits));
 }
 
 extern "C" LLVMMetadataRef
@@ -1182,10 +1172,7 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateEnumerationType(
       unwrapDI<DIDescriptor>(Scope), StringRef(Name, NameLen),
       unwrapDI<DIFile>(File), LineNumber, SizeInBits, AlignInBits,
       DINodeArray(unwrapDI<MDTuple>(Elements)), unwrapDI<DIType>(ClassTy),
-#if LLVM_VERSION_GE(18, 0)
-      /* RunTimeLang */ 0,
-#endif
-      "", IsScoped));
+      /* RunTimeLang */ 0, "", IsScoped));
 }
 
 extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateUnionType(
@@ -1552,27 +1539,19 @@ LLVMRustGetInstrProfIncrementIntrinsic(LLVMModuleRef M) {
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCParametersIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_parameters));
-#else
-  report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
-#endif
 }
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_tvbitmap_update));
-#else
-  report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
-#endif
 }
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_condbitmap_update));
 #else