1. Support ELF pcrel relocations for movw/movt:
R_ARM_MOVT_PREL and R_ARM_MOVW_PREL_NC.
2. Fix minor bug in ARMAsmPrinter - treat bitfield flag as a bitfield, not an enum.
3. Add support for 3 new elf section types (no-ops)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123294 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMAsmBackend.cpp b/lib/Target/ARM/ARMAsmBackend.cpp
index c72e790..0d5a9af 100644
--- a/lib/Target/ARM/ARMAsmBackend.cpp
+++ b/lib/Target/ARM/ARMAsmBackend.cpp
@@ -78,6 +78,8 @@
{ "fixup_arm_thumb_bcc", 1, 8, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_movt_hi16", 0, 16, 0 },
{ "fixup_arm_movw_lo16", 0, 16, 0 },
+{ "fixup_arm_movt_hi16_pcrel", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
+{ "fixup_arm_movw_lo16_pcrel", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
};
if (Kind < FirstTargetFixupKind)
@@ -156,7 +158,9 @@
case FK_Data_4:
return Value;
case ARM::fixup_arm_movt_hi16:
- case ARM::fixup_arm_movw_lo16: {
+ case ARM::fixup_arm_movw_lo16:
+ case ARM::fixup_arm_movt_hi16_pcrel:
+ case ARM::fixup_arm_movw_lo16_pcrel: {
unsigned Hi4 = (Value & 0xF000) >> 12;
unsigned Lo12 = Value & 0x0FFF;
// inst{19-16} = Hi4;
diff --git a/lib/Target/ARM/ARMAsmPrinter.cpp b/lib/Target/ARM/ARMAsmPrinter.cpp
index d1a975d..cce1576 100644
--- a/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -189,10 +189,10 @@
int64_t Imm = MO.getImm();
O << '#';
if ((Modifier && strcmp(Modifier, "lo16") == 0) ||
- (TF == ARMII::MO_LO16))
+ (TF & ARMII::MO_LO16))
O << ":lower16:";
else if ((Modifier && strcmp(Modifier, "hi16") == 0) ||
- (TF == ARMII::MO_HI16))
+ (TF & ARMII::MO_HI16))
O << ":upper16:";
O << Imm;
break;
diff --git a/lib/Target/ARM/ARMFixupKinds.h b/lib/Target/ARM/ARMFixupKinds.h
index 3e0bd0e..12efcb2 100644
--- a/lib/Target/ARM/ARMFixupKinds.h
+++ b/lib/Target/ARM/ARMFixupKinds.h
@@ -74,6 +74,11 @@
fixup_arm_movt_hi16, // :upper16:
fixup_arm_movw_lo16, // :lower16:
+ // It is possible to create an "immediate" that happens to be pcrel.
+ // Needed to support ELF::R_ARM_MOVT_PREL and ELF::R_ARM_MOVW_PREL_NC
+ fixup_arm_movt_hi16_pcrel, // :upper16:
+ fixup_arm_movw_lo16_pcrel, // :lower16:
+
// Marker
LastTargetFixupKind,
NumTargetFixupKinds = LastTargetFixupKind - FirstTargetFixupKind
diff --git a/lib/Target/ARM/ARMMCCodeEmitter.cpp b/lib/Target/ARM/ARMMCCodeEmitter.cpp
index 0e69221..4b328ee 100644
--- a/lib/Target/ARM/ARMMCCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMMCCodeEmitter.cpp
@@ -626,6 +626,32 @@
return Binary;
}
+// FIXME: This routine needs to handle more MCExpr types
+static const MCSymbolRefExpr *FindLHSymExpr(const MCExpr *E) {
+ // recurse left child until finding a MCSymbolRefExpr
+ switch (E->getKind()) {
+ case MCExpr::SymbolRef:
+ return cast<MCSymbolRefExpr>(E);
+ case MCExpr::Binary:
+ return FindLHSymExpr(cast<MCBinaryExpr>(E)->getLHS());
+ default:
+ return NULL;
+ }
+}
+
+// FIXME: This routine assumes that a binary
+// expression will always result in a PCRel expression
+// In reality, its only true if one or more subexpressions
+// is itself a PCRel (i.e. "." in asm or some other pcrel construct)
+// but this is good enough for now.
+static bool EvaluateAsPCRel(const MCExpr *Expr) {
+ switch (Expr->getKind()) {
+ case MCExpr::SymbolRef: return false;
+ case MCExpr::Binary: return true;
+ default: assert(0 && "Unexpected expression type");
+ }
+}
+
uint32_t ARMMCCodeEmitter::
getMovtImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
@@ -635,18 +661,27 @@
if (MO.isImm()) {
return static_cast<unsigned>(MO.getImm());
} else if (const MCSymbolRefExpr *Expr =
- dyn_cast<MCSymbolRefExpr>(MO.getExpr())) {
+ FindLHSymExpr(MO.getExpr())) {
+ // FIXME: :lower16: and :upper16: should be applicable to
+ // to whole expression, not just symbolrefs
+ // Until that change takes place, this hack is required to
+ // generate working code.
+ const MCExpr *OrigExpr = MO.getExpr();
MCFixupKind Kind;
switch (Expr->getKind()) {
default: assert(0 && "Unsupported ARMFixup");
case MCSymbolRefExpr::VK_ARM_HI16:
Kind = MCFixupKind(ARM::fixup_arm_movt_hi16);
+ if (EvaluateAsPCRel(OrigExpr))
+ Kind = MCFixupKind(ARM::fixup_arm_movt_hi16_pcrel);
break;
case MCSymbolRefExpr::VK_ARM_LO16:
Kind = MCFixupKind(ARM::fixup_arm_movw_lo16);
+ if (EvaluateAsPCRel(OrigExpr))
+ Kind = MCFixupKind(ARM::fixup_arm_movw_lo16_pcrel);
break;
}
- Fixups.push_back(MCFixup::Create(0, Expr, Kind));
+ Fixups.push_back(MCFixup::Create(0, OrigExpr, Kind));
return 0;
};
llvm_unreachable("Unsupported MCExpr type in MCOperand!");