[llvm-commits] [llvm] r123294 - in /llvm/trunk: lib/MC/ELFObjectWriter.cpp lib/Target/ARM/ARMAsmBackend.cpp lib/Target/ARM/ARMAsmPrinter.cpp lib/Target/ARM/ARMFixupKinds.h lib/Target/ARM/ARMMCCodeEmitter.cpp test/MC/ARM/elf-movt.s
Jason W Kim
jason.w.kim.2009 at gmail.com
Tue Jan 11 16:19:25 PST 2011
Author: jasonwkim
Date: Tue Jan 11 18:19:25 2011
New Revision: 123294
URL: http://llvm.org/viewvc/llvm-project?rev=123294&view=rev
Log:
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)
Modified:
llvm/trunk/lib/MC/ELFObjectWriter.cpp
llvm/trunk/lib/Target/ARM/ARMAsmBackend.cpp
llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
llvm/trunk/lib/Target/ARM/ARMFixupKinds.h
llvm/trunk/lib/Target/ARM/ARMMCCodeEmitter.cpp
llvm/trunk/test/MC/ARM/elf-movt.s
Modified: llvm/trunk/lib/MC/ELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/ELFObjectWriter.cpp?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/lib/MC/ELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/ELFObjectWriter.cpp Tue Jan 11 18:19:25 2011
@@ -1268,6 +1268,9 @@
case ELF::SHT_NOTE:
case ELF::SHT_NULL:
case ELF::SHT_ARM_ATTRIBUTES:
+ case ELF::SHT_INIT_ARRAY:
+ case ELF::SHT_FINI_ARRAY:
+ case ELF::SHT_PREINIT_ARRAY:
// Nothing to do.
break;
@@ -1490,6 +1493,13 @@
default:
Type = ELF::R_ARM_CALL; break;
} break;
+ case ARM::fixup_arm_movt_hi16:
+ case ARM::fixup_arm_movt_hi16_pcrel:
+ Type = ELF::R_ARM_MOVT_PREL; break;
+ case ARM::fixup_arm_movw_lo16:
+ case ARM::fixup_arm_movw_lo16_pcrel:
+ Type = ELF::R_ARM_MOVW_PREL_NC; break;
+
}
} else {
switch ((unsigned)Fixup.getKind()) {
Modified: llvm/trunk/lib/Target/ARM/ARMAsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmBackend.cpp?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMAsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMAsmBackend.cpp Tue Jan 11 18:19:25 2011
@@ -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;
Modified: llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp Tue Jan 11 18:19:25 2011
@@ -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;
Modified: llvm/trunk/lib/Target/ARM/ARMFixupKinds.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMFixupKinds.h?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMFixupKinds.h (original)
+++ llvm/trunk/lib/Target/ARM/ARMFixupKinds.h Tue Jan 11 18:19:25 2011
@@ -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
Modified: llvm/trunk/lib/Target/ARM/ARMMCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMMCCodeEmitter.cpp?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMMCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMMCCodeEmitter.cpp Tue Jan 11 18:19:25 2011
@@ -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!");
Modified: llvm/trunk/test/MC/ARM/elf-movt.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/elf-movt.s?rev=123294&r1=123293&r2=123294&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/elf-movt.s (original)
+++ llvm/trunk/test/MC/ARM/elf-movt.s Tue Jan 11 18:19:25 2011
@@ -1,4 +1,6 @@
@ RUN: llvm-mc %s -triple=armv7-linux-gnueabi | FileCheck -check-prefix=ASM %s
+@ RUN: llvm-mc %s -triple=armv7-linux-gnueabi -filetype=obj -o - | \
+@ RUN: elf-dump --dump-section-data | FileCheck -check-prefix=OBJ %s
.syntax unified
.text
.globl barf
@@ -12,3 +14,26 @@
@ ASM: movw r0, :lower16:GOT-(.LPC0_2+8)
@ ASM-NEXT: movt r0, :upper16:GOT-(.LPC0_2+16)
+@@ make sure that the text section fixups are sane too
+@ OBJ: '.text'
+@ OBJ-NEXT: 'sh_type', 0x00000001
+@ OBJ-NEXT: 'sh_flags', 0x00000006
+@ OBJ-NEXT: 'sh_addr', 0x00000000
+@ OBJ-NEXT: 'sh_offset', 0x00000034
+@ OBJ-NEXT: 'sh_size', 0x00000008
+@ OBJ-NEXT: 'sh_link', 0x00000000
+@ OBJ-NEXT: 'sh_info', 0x00000000
+@ OBJ-NEXT: 'sh_addralign', 0x00000004
+@ OBJ-NEXT: 'sh_entsize', 0x00000000
+@ OBJ-NEXT: '_section_data', 'f00f0fe3 ec0f4fe3'
+
+@ OBJ: Relocation 0x00000000
+@ OBJ-NEXT: 'r_offset', 0x00000000
+@ OBJ-NEXT: 'r_sym'
+@ OBJ-NEXT: 'r_type', 0x0000002d
+
+@ OBJ: Relocation 0x00000001
+@ OBJ-NEXT: 'r_offset', 0x00000004
+@ OBJ-NEXT: 'r_sym'
+@ OBJ-NEXT: 'r_type', 0x0000002e
+
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