[AVR] Force relocations for non-encodable jumps

llvm · Jan 2, 2025 · 0f27b8d · 0f27b8d
1 parent 207e485
commit 0f27b8d
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Showing 24 changed files with 102 additions and 47 deletions.
diff --git a/llvm/include/llvm/MC/MCAsmBackend.h b/llvm/include/llvm/MC/MCAsmBackend.h
@@ -96,6 +96,7 @@ class MCAsmBackend {
   virtual bool shouldForceRelocation(const MCAssembler &Asm,
                                      const MCFixup &Fixup,
                                      const MCValue &Target,
+                                     const uint64_t Value,
                                      const MCSubtargetInfo *STI) {
     return false;
   }

diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
@@ -222,7 +222,7 @@ bool MCAssembler::evaluateFixup(const MCFixup &Fixup, const MCFragment *DF,
 
   // Let the backend force a relocation if needed.
   if (IsResolved &&
-      getBackend().shouldForceRelocation(*this, Fixup, Target, STI)) {
+      getBackend().shouldForceRelocation(*this, Fixup, Target, Value, STI)) {
     IsResolved = false;
     WasForced = true;
   }

diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -98,7 +98,7 @@ class AArch64AsmBackend : public MCAsmBackend {
   unsigned getFixupKindContainereSizeInBytes(unsigned Kind) const;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 };
 
@@ -520,6 +520,7 @@ bool AArch64AsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
 bool AArch64AsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                               const MCFixup &Fixup,
                                               const MCValue &Target,
+                                              const uint64_t,
                                               const MCSubtargetInfo *STI) {
   unsigned Kind = Fixup.getKind();
   if (Kind >= FirstLiteralRelocationKind)

diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
@@ -53,7 +53,7 @@ class AMDGPUAsmBackend : public MCAsmBackend {
   std::optional<MCFixupKind> getFixupKind(StringRef Name) const override;
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 };
 
@@ -196,7 +196,7 @@ const MCFixupKindInfo &AMDGPUAsmBackend::getFixupKindInfo(
 
 bool AMDGPUAsmBackend::shouldForceRelocation(const MCAssembler &,
                                              const MCFixup &Fixup,
-                                             const MCValue &,
+                                             const MCValue &, const uint64_t,
                                              const MCSubtargetInfo *STI) {
   return Fixup.getKind() >= FirstLiteralRelocationKind;
 }

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -955,7 +955,7 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
 
 bool ARMAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                           const MCFixup &Fixup,
-                                          const MCValue &Target,
+                                          const MCValue &Target, const uint64_t,
                                           const MCSubtargetInfo *STI) {
   const MCSymbolRefExpr *A = Target.getSymA();
   const MCSymbol *Sym = A ? &A->getSymbol() : nullptr;

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h
@@ -36,7 +36,7 @@ class ARMAsmBackend : public MCAsmBackend {
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
   unsigned adjustFixupValue(const MCAssembler &Asm, const MCFixup &Fixup,

diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
@@ -31,10 +31,14 @@ namespace adjust {
 
 using namespace llvm;
 
-static void signed_width(unsigned Width, uint64_t Value,
-                         std::string Description, const MCFixup &Fixup,
-                         MCContext *Ctx) {
-  if (!isIntN(Width, Value)) {
+static bool checkSignedWidth(unsigned Width, uint64_t Value,
+                             std::string Description, const MCFixup &Fixup,
+                             MCContext *Ctx) {
+  if (isIntN(Width, Value)) {
+    return true;
+  }
+
+  if (Ctx) {
     std::string Diagnostic = "out of range " + Description;
 
     int64_t Min = minIntN(Width);
@@ -45,12 +49,18 @@ static void signed_width(unsigned Width, uint64_t Value,
 
     Ctx->reportError(Fixup.getLoc(), Diagnostic);
   }
+
+  return false;
 }
 
-static void unsigned_width(unsigned Width, uint64_t Value,
-                           std::string Description, const MCFixup &Fixup,
-                           MCContext *Ctx) {
-  if (!isUIntN(Width, Value)) {
+static bool checkUnsignedWidth(unsigned Width, uint64_t Value,
+                               std::string Description, const MCFixup &Fixup,
+                               MCContext *Ctx) {
+  if (isUIntN(Width, Value)) {
+    return true;
+  }
+
+  if (Ctx) {
     std::string Diagnostic = "out of range " + Description;
 
     int64_t Max = maxUIntN(Width);
@@ -60,31 +70,37 @@ static void unsigned_width(unsigned Width, uint64_t Value,
 
     Ctx->reportError(Fixup.getLoc(), Diagnostic);
   }
+
+  return false;
 }
 
 /// Adjusts the value of a branch target before fixup application.
 static void adjustBranch(unsigned Size, const MCFixup &Fixup, uint64_t &Value,
                          MCContext *Ctx) {
   // We have one extra bit of precision because the value is rightshifted by
   // one.
-  unsigned_width(Size + 1, Value, std::string("branch target"), Fixup, Ctx);
+  checkUnsignedWidth(Size + 1, Value, std::string("branch target"), Fixup, Ctx);
 
   // Rightshifts the value by one.
   AVR::fixups::adjustBranchTarget(Value);
 }
 
 /// Adjusts the value of a relative branch target before fixup application.
-static void adjustRelativeBranch(unsigned Size, const MCFixup &Fixup,
-                                 uint64_t &Value, MCContext *Ctx) {
+static bool adjustRelativeBranch(unsigned Size, const MCFixup &Fixup,
+                                 uint64_t &Value, MCContext *Ctx,
+                                 const MCSubtargetInfo *STI = nullptr) {
   // Jumps are relative to the current instruction.
   Value -= 2;
 
   // We have one extra bit of precision because the value is rightshifted by
   // one.
   Size += 1;
 
-  if (!isIntN(Size, Value) &&
-      Ctx->getSubtargetInfo()->hasFeature(AVR::FeatureWrappingRjmp)) {
+  if (!STI) {
+    STI = Ctx->getSubtargetInfo();
+  }
+
+  if (!isIntN(Size, Value) && STI->hasFeature(AVR::FeatureWrappingRjmp)) {
     const int32_t FlashSize = 0x2000;
     int32_t SignedValue = Value;
 
@@ -96,10 +112,15 @@ static void adjustRelativeBranch(unsigned Size, const MCFixup &Fixup,
     }
   }
 
-  signed_width(Size, Value, std::string("branch target"), Fixup, Ctx);
+  if (!checkSignedWidth(Size, Value, std::string("branch target"), Fixup,
+                        Ctx)) {
+    return false;
+  }
 
   // Rightshifts the value by one.
   AVR::fixups::adjustBranchTarget(Value);
+
+  return true;
 }
 
 /// 22-bit absolute fixup.
@@ -152,7 +173,7 @@ static void fixup_13_pcrel(unsigned Size, const MCFixup &Fixup, uint64_t &Value,
 /// Resolves to:
 /// 10q0 qq10 0000 1qqq
 static void fixup_6(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
-  unsigned_width(6, Value, std::string("immediate"), Fixup, Ctx);
+  checkUnsignedWidth(6, Value, std::string("immediate"), Fixup, Ctx);
 
   Value = ((Value & 0x20) << 8) | ((Value & 0x18) << 7) | (Value & 0x07);
 }
@@ -164,7 +185,7 @@ static void fixup_6(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
 /// 0000 0000 kk00 kkkk
 static void fixup_6_adiw(const MCFixup &Fixup, uint64_t &Value,
                          MCContext *Ctx) {
-  unsigned_width(6, Value, std::string("immediate"), Fixup, Ctx);
+  checkUnsignedWidth(6, Value, std::string("immediate"), Fixup, Ctx);
 
   Value = ((Value & 0x30) << 2) | (Value & 0x0f);
 }
@@ -174,7 +195,7 @@ static void fixup_6_adiw(const MCFixup &Fixup, uint64_t &Value,
 /// Resolves to:
 /// 0000 0000 AAAA A000
 static void fixup_port5(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
-  unsigned_width(5, Value, std::string("port number"), Fixup, Ctx);
+  checkUnsignedWidth(5, Value, std::string("port number"), Fixup, Ctx);
 
   Value &= 0x1f;
 
@@ -186,7 +207,7 @@ static void fixup_port5(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
 /// Resolves to:
 /// 1011 0AAd dddd AAAA
 static void fixup_port6(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
-  unsigned_width(6, Value, std::string("port number"), Fixup, Ctx);
+  checkUnsignedWidth(6, Value, std::string("port number"), Fixup, Ctx);
 
   Value = ((Value & 0x30) << 5) | (Value & 0x0f);
 }
@@ -197,7 +218,7 @@ static void fixup_port6(const MCFixup &Fixup, uint64_t &Value, MCContext *Ctx) {
 /// 1010 ikkk dddd kkkk
 static void fixup_lds_sts_16(const MCFixup &Fixup, uint64_t &Value,
                              MCContext *Ctx) {
-  unsigned_width(7, Value, std::string("immediate"), Fixup, Ctx);
+  checkUnsignedWidth(7, Value, std::string("immediate"), Fixup, Ctx);
   Value = ((Value & 0x70) << 8) | (Value & 0x0f);
 }
 
@@ -331,13 +352,15 @@ void AVRAsmBackend::adjustFixupValue(const MCFixup &Fixup,
     adjust::ldi::ms8(Size, Fixup, Value, Ctx);
     break;
   case AVR::fixup_16:
-    adjust::unsigned_width(16, Value, std::string("port number"), Fixup, Ctx);
+    adjust::checkUnsignedWidth(16, Value, std::string("port number"), Fixup,
+                               Ctx);
 
     Value &= 0xffff;
     break;
   case AVR::fixup_16_pm:
     Value >>= 1; // Flash addresses are always shifted.
-    adjust::unsigned_width(16, Value, std::string("port number"), Fixup, Ctx);
+    adjust::checkUnsignedWidth(16, Value, std::string("port number"), Fixup,
+                               Ctx);
 
     Value &= 0xffff;
     break;
@@ -512,14 +535,25 @@ bool AVRAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
 bool AVRAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                           const MCFixup &Fixup,
                                           const MCValue &Target,
+                                          const uint64_t Value,
                                           const MCSubtargetInfo *STI) {
   switch ((unsigned)Fixup.getKind()) {
   default:
     return Fixup.getKind() >= FirstLiteralRelocationKind;
+
   case AVR::fixup_7_pcrel:
-  case AVR::fixup_13_pcrel:
-    // Always resolve relocations for PC-relative branches
-    return false;
+  case AVR::fixup_13_pcrel: {
+    uint64_t ValueEx = Value;
+    uint64_t Size = AVRAsmBackend::getFixupKindInfo(Fixup.getKind()).TargetSize;
+
+    // If the jump is too large to encode it, fall back to a relocation.
+    //
+    // Note that trying to actually link that relocation *would* fail, but the
+    // hopes are that the module we're currently compiling won't be actually
+    // linked to the final binary.
+    return !adjust::adjustRelativeBranch(Size, Fixup, ValueEx, nullptr, STI);
+  }
+
   case AVR::fixup_call:
     return true;
   }

diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h
@@ -53,7 +53,7 @@ class AVRAsmBackend : public MCAsmBackend {
                     const MCSubtargetInfo *STI) const override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
 private:

diff --git a/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.cpp b/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.cpp
@@ -262,6 +262,7 @@ bool CSKYAsmBackend::mayNeedRelaxation(const MCInst &Inst,
 bool CSKYAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                            const MCFixup &Fixup,
                                            const MCValue &Target,
+                                           const uint64_t /*Value*/,
                                            const MCSubtargetInfo * /*STI*/) {
   if (Fixup.getKind() >= FirstLiteralRelocationKind)
     return true;

diff --git a/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.h b/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.h
@@ -52,7 +52,7 @@ class CSKYAsmBackend : public MCAsmBackend {
                     const MCSubtargetInfo *STI) const override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
   std::unique_ptr<MCObjectTargetWriter>

diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp
@@ -201,7 +201,7 @@ class HexagonAsmBackend : public MCAsmBackend {
   }
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t,
                              const MCSubtargetInfo *STI) override {
     switch(Fixup.getTargetKind()) {
       default:

diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
@@ -251,6 +251,7 @@ bool LoongArchAsmBackend::shouldInsertFixupForCodeAlign(MCAssembler &Asm,
 bool LoongArchAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                                 const MCFixup &Fixup,
                                                 const MCValue &Target,
+                                                const uint64_t,
                                                 const MCSubtargetInfo *STI) {
   if (Fixup.getKind() >= FirstLiteralRelocationKind)
     return true;

diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
@@ -57,7 +57,7 @@ class LoongArchAsmBackend : public MCAsmBackend {
                                      MCAlignFragment &AF) override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
   unsigned getNumFixupKinds() const override {

diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -542,6 +542,7 @@ bool MipsAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
 bool MipsAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                            const MCFixup &Fixup,
                                            const MCValue &Target,
+                                           const uint64_t,
                                            const MCSubtargetInfo *STI) {
   if (Fixup.getKind() >= FirstLiteralRelocationKind)
     return true;

diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.h b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.h
@@ -55,7 +55,7 @@ class MipsAsmBackend : public MCAsmBackend {
                     const MCSubtargetInfo *STI) const override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
   bool isMicroMips(const MCSymbol *Sym) const override;

diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
@@ -161,7 +161,7 @@ class PPCAsmBackend : public MCAsmBackend {
   }
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t,
                              const MCSubtargetInfo *STI) override {
     MCFixupKind Kind = Fixup.getKind();
     switch ((unsigned)Kind) {

diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -112,6 +112,7 @@ RISCVAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 bool RISCVAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                             const MCFixup &Fixup,
                                             const MCValue &Target,
+                                            const uint64_t,
                                             const MCSubtargetInfo *STI) {
   if (Fixup.getKind() >= FirstLiteralRelocationKind)
     return true;
@@ -567,7 +568,7 @@ bool RISCVAsmBackend::evaluateTargetFixup(const MCAssembler &Asm,
   Value = Asm.getSymbolOffset(SA) + AUIPCTarget.getConstant();
   Value -= Asm.getFragmentOffset(*AUIPCDF) + AUIPCFixup->getOffset();
 
-  if (shouldForceRelocation(Asm, *AUIPCFixup, AUIPCTarget, STI)) {
+  if (shouldForceRelocation(Asm, *AUIPCFixup, AUIPCTarget, Value, STI)) {
     WasForced = true;
     return false;
   }

diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h
@@ -65,7 +65,7 @@ class RISCVAsmBackend : public MCAsmBackend {
   createObjectTargetWriter() const override;
 
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
 
   bool fixupNeedsRelaxationAdvanced(const MCAssembler &Asm,

diff --git a/llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp b/llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp
@@ -273,7 +273,7 @@ namespace {
     }
 
     bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                               const MCValue &Target,
+                               const MCValue &Target, const uint64_t,
                                const MCSubtargetInfo *STI) override {
       if (Fixup.getKind() >= FirstLiteralRelocationKind)
         return true;

diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
@@ -116,7 +116,7 @@ class SystemZMCAsmBackend : public MCAsmBackend {
   std::optional<MCFixupKind> getFixupKind(StringRef Name) const override;
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
-                             const MCValue &Target,
+                             const MCValue &Target, const uint64_t Value,
                              const MCSubtargetInfo *STI) override;
   void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                   const MCValue &Target, MutableArrayRef<char> Data,
@@ -161,7 +161,7 @@ SystemZMCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
 bool SystemZMCAsmBackend::shouldForceRelocation(const MCAssembler &,
                                                 const MCFixup &Fixup,
-                                                const MCValue &,
+                                                const MCValue &, const uint64_t,
                                                 const MCSubtargetInfo *STI) {
   return Fixup.getKind() >= FirstLiteralRelocationKind;
 }