From cfe77f23d6f190d54763a7575cee95aceb9216bc Mon Sep 17 00:00:00 2001 From: Guillaume Chatelet Date: Fri, 2 Dec 2022 10:08:08 +0000 Subject: [PATCH] [lld][Alignment][NFC] Use Align instead of log2 of alignment in Wasm Sections I intend to slowly upgrade all alignments to the Align type in lld as well. Some places talk about alignment in Bytes while other specify them as Log2(Bytes). Let's make sure all of this is coherent. Differential Revision: https://reviews.llvm.org/D139181 --- lld/wasm/InputChunks.h | 6 +++--- lld/wasm/OutputSegment.cpp | 13 +++++++------ lld/wasm/OutputSegment.h | 2 +- lld/wasm/SyntheticSections.cpp | 2 +- lld/wasm/Writer.cpp | 9 +++++---- 5 files changed, 17 insertions(+), 15 deletions(-) diff --git a/lld/wasm/InputChunks.h b/lld/wasm/InputChunks.h index fb2c43861945..37494172a69e 100644 --- a/lld/wasm/InputChunks.h +++ b/lld/wasm/InputChunks.h @@ -85,7 +85,7 @@ public: OutputSection *outputSec = nullptr; uint32_t comdat = UINT32_MAX; uint32_t inputSectionOffset = 0; - uint32_t alignment; + llvm::Align alignment; uint32_t flags; // Only applies to data segments. @@ -109,8 +109,8 @@ public: protected: InputChunk(ObjFile *f, Kind k, StringRef name, uint32_t alignment = 0, uint32_t flags = 0) - : name(name), file(f), alignment(alignment), flags(flags), sectionKind(k), - live(!config->gcSections), discarded(false) {} + : name(name), file(f), alignment(1ULL << alignment), flags(flags), + sectionKind(k), live(!config->gcSections), discarded(false) {} ArrayRef data() const { return rawData; } uint64_t getTombstone() const; diff --git a/lld/wasm/OutputSegment.cpp b/lld/wasm/OutputSegment.cpp index 86b538403391..e7e9929e3d9c 100644 --- a/lld/wasm/OutputSegment.cpp +++ b/lld/wasm/OutputSegment.cpp @@ -22,10 +22,10 @@ namespace wasm { void OutputSegment::addInputSegment(InputChunk *inSeg) { alignment = std::max(alignment, inSeg->alignment); inputSegments.push_back(inSeg); - size = llvm::alignTo(size, 1ULL << inSeg->alignment); + size = llvm::alignTo(size, inSeg->alignment); LLVM_DEBUG(dbgs() << "addInputSegment: " << inSeg->name << " oname=" << name - << " size=" << inSeg->getSize() - << " align=" << inSeg->alignment << " at:" << size << "\n"); + << " size=" << inSeg->getSize() << " align=" + << Log2(inSeg->alignment) << " at:" << size << "\n"); inSeg->outputSeg = this; inSeg->outputSegmentOffset = size; size += inSeg->getSize(); @@ -56,8 +56,9 @@ void OutputSegment::finalizeInputSegments() { }); if (i == mergedSegments.end()) { LLVM_DEBUG(llvm::dbgs() << "new merge segment: " << name - << " alignment=" << ms->alignment << "\n"); - auto *syn = make(name, ms->alignment, ms->flags); + << " alignment=" << Log2(ms->alignment) << "\n"); + auto *syn = + make(name, Log2(ms->alignment), ms->flags); syn->outputSeg = this; mergedSegments.push_back(syn); i = std::prev(mergedSegments.end()); @@ -74,7 +75,7 @@ void OutputSegment::finalizeInputSegments() { inputSegments = newSegments; size = 0; for (InputChunk *seg : inputSegments) { - size = llvm::alignTo(size, 1ULL << seg->alignment); + size = llvm::alignTo(size, seg->alignment); LLVM_DEBUG(llvm::dbgs() << "outputSegmentOffset set: " << seg->name << " -> " << size << "\n"); seg->outputSegmentOffset = size; diff --git a/lld/wasm/OutputSegment.h b/lld/wasm/OutputSegment.h index 3b7a0f50be94..5be6a7184c37 100644 --- a/lld/wasm/OutputSegment.h +++ b/lld/wasm/OutputSegment.h @@ -38,7 +38,7 @@ public: uint32_t linkingFlags = 0; uint32_t initFlags = 0; uint32_t sectionOffset = 0; - uint32_t alignment = 0; + llvm::Align alignment; uint64_t startVA = 0; std::vector inputSegments; diff --git a/lld/wasm/SyntheticSections.cpp b/lld/wasm/SyntheticSections.cpp index 1cded0e49a0d..9411aa4233aa 100644 --- a/lld/wasm/SyntheticSections.cpp +++ b/lld/wasm/SyntheticSections.cpp @@ -668,7 +668,7 @@ void LinkingSection::writeBody() { writeUleb128(sub.os, dataSegments.size(), "num data segments"); for (const OutputSegment *s : dataSegments) { writeStr(sub.os, s->name, "segment name"); - writeUleb128(sub.os, s->alignment, "alignment"); + writeUleb128(sub.os, Log2(s->alignment), "alignment"); writeUleb128(sub.os, s->linkingFlags, "flags"); } sub.writeTo(os); diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp index 4e83b10afddb..6906da0ab693 100644 --- a/lld/wasm/Writer.cpp +++ b/lld/wasm/Writer.cpp @@ -288,11 +288,12 @@ void Writer::layoutMemory() { out.dylinkSec->memAlign = 0; for (OutputSegment *seg : segments) { - out.dylinkSec->memAlign = std::max(out.dylinkSec->memAlign, seg->alignment); - memoryPtr = alignTo(memoryPtr, 1ULL << seg->alignment); + out.dylinkSec->memAlign = + std::max(out.dylinkSec->memAlign, Log2(seg->alignment)); + memoryPtr = alignTo(memoryPtr, seg->alignment); seg->startVA = memoryPtr; log(formatv("mem: {0,-15} offset={1,-8} size={2,-8} align={3}", seg->name, - memoryPtr, seg->size, seg->alignment)); + memoryPtr, seg->size, Log2(seg->alignment))); if (!config->relocatable && seg->isTLS()) { if (WasmSym::tlsSize) { @@ -301,7 +302,7 @@ void Writer::layoutMemory() { } if (WasmSym::tlsAlign) { auto *tlsAlign = cast(WasmSym::tlsAlign); - setGlobalPtr(tlsAlign, int64_t{1} << seg->alignment); + setGlobalPtr(tlsAlign, seg->alignment.value()); } if (!config->sharedMemory && WasmSym::tlsBase) { auto *tlsBase = cast(WasmSym::tlsBase);