9 files changed, 138 insertions, 15 deletions

diff --git a/llvm/include/llvm/MC/MCAsmBackend.h b/llvm/include/llvm/MC/MCAsmBackend.h
index ecba355e15e..bc23488300e 100644
--- a/llvm/include/llvm/MC/MCAsmBackend.h
+++ b/llvm/include/llvm/MC/MCAsmBackend.h
@@ -99,7 +99,8 @@ public:
   virtual bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved,
                                             uint64_t Value,
                                             const MCRelaxableFragment *DF,
-                                            const MCAsmLayout &Layout) const;
+                                            const MCAsmLayout &Layout,
+                                            const bool WasForced) const;
 
   /// Simple predicate for targets where !Resolved implies requiring relaxation
   virtual bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
diff --git a/llvm/include/llvm/MC/MCAssembler.h b/llvm/include/llvm/MC/MCAssembler.h
index 2951f5ace1b..6a35bc1ed8c 100644
--- a/llvm/include/llvm/MC/MCAssembler.h
+++ b/llvm/include/llvm/MC/MCAssembler.h
@@ -162,12 +162,14 @@ private:
   /// evaluates to.
   /// \param Value [out] On return, the value of the fixup as currently laid
   /// out.
+  /// \param WasForced [out] On return, the value in the fixup is set to the
+  /// correct value if WasForced is true, even if evaluateFixup returns false.
   /// \return Whether the fixup value was fully resolved. This is true if the
   /// \p Value result is fixed, otherwise the value may change due to
   /// relocation.
   bool evaluateFixup(const MCAsmLayout &Layout, const MCFixup &Fixup,
                      const MCFragment *DF, MCValue &Target,
-                     uint64_t &Value) const;
+                     uint64_t &Value, bool &WasForced) const;
 
   /// Check whether a fixup can be satisfied, or whether it needs to be relaxed
   /// (increased in size, in order to hold its value correctly).
diff --git a/llvm/lib/MC/MCAsmBackend.cpp b/llvm/lib/MC/MCAsmBackend.cpp
index b4a4d0a8996..d675a98542f 100644
--- a/llvm/lib/MC/MCAsmBackend.cpp
+++ b/llvm/lib/MC/MCAsmBackend.cpp
@@ -58,7 +58,8 @@ const MCFixupKindInfo &MCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
 bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
     const MCFixup &Fixup, bool Resolved, uint64_t Value,
-    const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const {
+    const MCRelaxableFragment *DF, const MCAsmLayout &Layout,
+    const bool WasForced) const {
   if (!Resolved)
     return true;
   return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
@@ -84,4 +85,4 @@ void MCAsmBackend::handleCodePaddingInstructionEnd(const MCInst &Inst) {
 
 bool MCAsmBackend::relaxFragment(MCPaddingFragment *PF, MCAsmLayout &Layout) {
   return CodePadder->relaxFragment(PF, Layout);
-}
\ No newline at end of file
+}
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index b6af11d09ba..a8a0177dff6 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -197,7 +197,8 @@ const MCSymbol *MCAssembler::getAtom(const MCSymbol &S) const {
 
 bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
                                 const MCFixup &Fixup, const MCFragment *DF,
-                                MCValue &Target, uint64_t &Value) const {
+                                MCValue &Target, uint64_t &Value,
+                                bool &WasForced) const {
   ++stats::evaluateFixup;
 
   // FIXME: This code has some duplication with recordRelocation. We should
@@ -209,6 +210,7 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
   const MCExpr *Expr = Fixup.getValue();
   MCContext &Ctx = getContext();
   Value = 0;
+  WasForced = false;
   if (!Expr->evaluateAsRelocatable(Target, &Layout, &Fixup)) {
     Ctx.reportError(Fixup.getLoc(), "expected relocatable expression");
     return true;
@@ -273,8 +275,10 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
   }
 
   // Let the backend force a relocation if needed.
-  if (IsResolved && getBackend().shouldForceRelocation(*this, Fixup, Target))
+  if (IsResolved && getBackend().shouldForceRelocation(*this, Fixup, Target)) {
     IsResolved = false;
+    WasForced = true;
+  }
 
   return IsResolved;
 }
@@ -689,7 +693,9 @@ MCAssembler::handleFixup(const MCAsmLayout &Layout, MCFragment &F,
   // Evaluate the fixup.
   MCValue Target;
   uint64_t FixedValue;
-  bool IsResolved = evaluateFixup(Layout, Fixup, &F, Target, FixedValue);
+  bool WasForced;
+  bool IsResolved = evaluateFixup(Layout, Fixup, &F, Target, FixedValue,
+                                  WasForced);
   if (!IsResolved) {
     // The fixup was unresolved, we need a relocation. Inform the object
     // writer of the relocation, and give it an opportunity to adjust the
@@ -804,13 +810,14 @@ bool MCAssembler::fixupNeedsRelaxation(const MCFixup &Fixup,
   assert(getBackendPtr() && "Expected assembler backend");
   MCValue Target;
   uint64_t Value;
-  bool Resolved = evaluateFixup(Layout, Fixup, DF, Target, Value);
+  bool WasForced;
+  bool Resolved = evaluateFixup(Layout, Fixup, DF, Target, Value, WasForced);
   if (Target.getSymA() &&
       Target.getSymA()->getKind() == MCSymbolRefExpr::VK_X86_ABS8 &&
       Fixup.getKind() == FK_Data_1)
     return false;
   return getBackend().fixupNeedsRelaxationAdvanced(Fixup, Resolved, Value, DF,
-                                                   Layout);
+                                                   Layout, WasForced);
 }
 
 bool MCAssembler::fragmentNeedsRelaxation(const MCRelaxableFragment *F,
diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp
index 584f35e0051..b950da2c169 100644
--- a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp
+++ b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp
@@ -569,7 +569,8 @@ public:
   bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved,
                                     uint64_t Value,
                                     const MCRelaxableFragment *DF,
-                                    const MCAsmLayout &Layout) const override {
+                                    const MCAsmLayout &Layout,
+                                    const bool WasForced) const override {
     MCInst const &MCB = DF->getInst();
     assert(HexagonMCInstrInfo::isBundle(MCB));
 
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
index 9c4ca811ce3..5b5663b07d0 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -53,7 +53,15 @@ public:
 
   bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
                             const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override;
+                            const MCAsmLayout &Layout) const override {
+    llvm_unreachable("Handled by fixupNeedsRelaxationAdvanced");
+  }
+
+  bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved,
+                                    uint64_t Value,
+                                    const MCRelaxableFragment *DF,
+                                    const MCAsmLayout &Layout,
+                                    const bool WasForced) const override;
 
   unsigned getNumFixupKinds() const override {
     return RISCV::NumTargetFixupKinds;
@@ -96,10 +104,19 @@ public:
 };
 
 
-bool RISCVAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
-                                           uint64_t Value,
-                                           const MCRelaxableFragment *DF,
-                                           const MCAsmLayout &Layout) const {
+bool RISCVAsmBackend::fixupNeedsRelaxationAdvanced(const MCFixup &Fixup,
+                                                   bool Resolved,
+                                                   uint64_t Value,
+                                                   const MCRelaxableFragment *DF,
+                                                   const MCAsmLayout &Layout,
+                                                   const bool WasForced) const {
+  // Return true if the symbol is actually unresolved.
+  // Resolved could be always false when shouldForceRelocation return true.
+  // We use !WasForced to indicate that the symbol is unresolved and not forced
+  // by shouldForceRelocation.
+  if (!Resolved && !WasForced)
+    return true;
+
   int64_t Offset = int64_t(Value);
   switch ((unsigned)Fixup.getKind()) {
   default:
diff --git a/llvm/test/MC/RISCV/compressed-relocations.s b/llvm/test/MC/RISCV/compressed-relocations.s
index 832a2085e61..31c398ef84e 100644
--- a/llvm/test/MC/RISCV/compressed-relocations.s
+++ b/llvm/test/MC/RISCV/compressed-relocations.s
@@ -2,6 +2,8 @@
 # RUN:     | FileCheck -check-prefix=INSTR -check-prefix=FIXUP %s
 # RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c < %s \
 # RUN:     | llvm-readobj -r | FileCheck -check-prefix=RELOC %s
+# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c,+relax < %s \
+# RUN:     | llvm-readobj -r | FileCheck -check-prefix=RELOC %s
 
 # Check prefixes:
 # RELOC - Check the relocation in the object.
diff --git a/llvm/test/MC/RISCV/rv32-relaxation.s b/llvm/test/MC/RISCV/rv32-relaxation.s
index 8b1675d3389..09a833a790f 100644
--- a/llvm/test/MC/RISCV/rv32-relaxation.s
+++ b/llvm/test/MC/RISCV/rv32-relaxation.s
@@ -1,5 +1,9 @@
 # RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c < %s \
 # RUN:     | llvm-objdump -d -riscv-no-aliases - | FileCheck -check-prefix=INSTR %s
+# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c,+relax < %s \
+# RUN:     | llvm-objdump -d -riscv-no-aliases - | FileCheck -check-prefix=RELAX-INSTR %s
+# RUN: llvm-mc -filetype=obj -triple riscv32 -mattr=+c,+relax < %s \
+# RUN:     | llvm-readobj -r | FileCheck -check-prefix=RELAX-RELOC %s
 
 FAR_JUMP_NEGATIVE:
   c.nop
@@ -15,55 +19,103 @@ NEAR_NEGATIVE:
 start:
   c.bnez a0, NEAR
 #INSTR: c.bnez a0, 72
+#RELAX-INSTR: c.bnez a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.bnez a0, NEAR_NEGATIVE
 #INSTR: c.bnez a0, -4
+#RELAX-INSTR: c.bnez a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.bnez a0, FAR_BRANCH
 #INSTR-NEXT: bne a0, zero, 326
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: bne a0, zero, -268
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_JUMP
 #INSTR-NEXT: bne a0, zero, 2320
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_JUMP_NEGATIVE
 #INSTR-NEXT: bne a0, zero, -2278
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
 
   c.beqz a0, NEAR
 #INSTR-NEXT: c.beqz a0, 52
+#RELAX-INSTR-NEXT: c.beqz a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.beqz a0, NEAR_NEGATIVE
 #INSTR-NEXT: c.beqz a0, -24
+#RELAX-INSTR-NEXT: c.beqz a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.beqz a0, FAR_BRANCH
 #INSTR-NEXT: beq a0, zero, 306
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: beq a0, zero, -288
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_JUMP
 #INSTR-NEXT: beq a0, zero, 2300
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_JUMP_NEGATIVE
 #INSTR-NEXT: beq a0, zero, -2298
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
 
   c.j NEAR
 #INSTR-NEXT: c.j 32
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j NEAR_NEGATIVE
 #INSTR-NEXT: c.j -44
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_BRANCH
 #INSTR-NEXT: c.j 286
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: c.j -306
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_JUMP
 #INSTR-NEXT: jal zero, 2284
+#RELAX-INSTR-NEXT: jal zero, 0
+#RELAX-RELOC: R_RISCV_JAL
   c.j FAR_JUMP_NEGATIVE
 #INSTR-NEXT: jal zero, -2314
+#RELAX-INSTR-NEXT: jal zero, 0
+#RELAX-RELOC: R_RISCV_JAL
 
   c.jal NEAR
 #INSTR: c.jal 16
+#RELAX-INSTR: c.jal 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.jal NEAR_NEGATIVE
 #INSTR: c.jal -60
+#RELAX-INSTR: c.jal 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.jal FAR_BRANCH
 #INSTR-NEXT: c.jal 270
+#RELAX-INSTR-NEXT: c.jal 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.jal FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: c.jal -322
+#RELAX-INSTR-NEXT: c.jal 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.jal FAR_JUMP
 #INSTR-NEXT: jal ra, 2268
+#RELAX-INSTR-NEXT: jal ra, 0
+#RELAX-RELOC: R_RISCV_JAL
   c.jal FAR_JUMP_NEGATIVE
 #INSTR-NEXT: jal ra, -2330
+#RELAX-INSTR-NEXT: jal ra, 0
+#RELAX-RELOC: R_RISCV_JAL
 
 NEAR:
   c.nop
diff --git a/llvm/test/MC/RISCV/rv64-relaxation.s b/llvm/test/MC/RISCV/rv64-relaxation.s
index f0551244665..202cbafa785 100644
--- a/llvm/test/MC/RISCV/rv64-relaxation.s
+++ b/llvm/test/MC/RISCV/rv64-relaxation.s
@@ -1,5 +1,9 @@
 # RUN: llvm-mc -filetype=obj -triple riscv64 -mattr=+c < %s \
 # RUN:     | llvm-objdump -d -riscv-no-aliases - | FileCheck -check-prefix=INSTR %s
+# RUN: llvm-mc -filetype=obj -triple riscv64 -mattr=+c,+relax < %s \
+# RUN:     | llvm-objdump -d -riscv-no-aliases - | FileCheck -check-prefix=RELAX-INSTR %s
+# RUN: llvm-mc -filetype=obj -triple riscv64 -mattr=+c,+relax < %s \
+# RUN:     | llvm-readobj -r | FileCheck -check-prefix=RELAX-RELOC %s
 
 FAR_JUMP_NEGATIVE:
   c.nop
@@ -15,42 +19,78 @@ NEAR_NEGATIVE:
 start:
   c.bnez a0, NEAR
 #INSTR: c.bnez a0, 56
+#RELAX-INSTR: c.bnez a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.bnez a0, NEAR_NEGATIVE
 #INSTR: c.bnez a0, -4
+#RELAX-INSTR: c.bnez a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.bnez a0, FAR_BRANCH
 #INSTR-NEXT: bne a0, zero, 310
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: bne a0, zero, -268
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_JUMP
 #INSTR-NEXT: bne a0, zero, 2304
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.bnez a0, FAR_JUMP_NEGATIVE
 #INSTR-NEXT: bne a0, zero, -2278
+#RELAX-INSTR-NEXT: bne a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
 
   c.beqz a0, NEAR
 #INSTR-NEXT: c.beqz a0, 36
+#RELAX-INSTR-NEXT: c.beqz a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.beqz a0, NEAR_NEGATIVE
 #INSTR-NEXT: c.beqz a0, -24
+#RELAX-INSTR-NEXT: c.beqz a0, 0
+#RELAX-RELOC: R_RISCV_RVC_BRANCH
   c.beqz a0, FAR_BRANCH
 #INSTR-NEXT: beq a0, zero, 290
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: beq a0, zero, -288
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_JUMP
 #INSTR-NEXT: beq a0, zero, 2284
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
   c.beqz a0, FAR_JUMP_NEGATIVE
 #INSTR-NEXT: beq a0, zero, -2298
+#RELAX-INSTR-NEXT: beq a0, zero, 0
+#RELAX-RELOC: R_RISCV_BRANCH
 
   c.j NEAR
 #INSTR-NEXT: c.j 16
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j NEAR_NEGATIVE
 #INSTR-NEXT: c.j -44
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_BRANCH
 #INSTR-NEXT: c.j 270
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_BRANCH_NEGATIVE
 #INSTR-NEXT: c.j -306
+#RELAX-INSTR-NEXT: c.j 0
+#RELAX-RELOC: R_RISCV_RVC_JUMP
   c.j FAR_JUMP
 #INSTR-NEXT: jal zero, 2268
+#RELAX-INSTR-NEXT: jal zero, 0
+#RELAX-RELOC: R_RISCV_JAL
   c.j FAR_JUMP_NEGATIVE
 #INSTR-NEXT: jal zero, -2314
+#RELAX-INSTR-NEXT: jal zero, 0
+#RELAX-RELOC: R_RISCV_JAL
 
 NEAR:
   c.nop