[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
Evan Cheng
evan.cheng at apple.com
Wed Jan 12 10:49:45 PST 2011
On Jan 11, 2011, at 4:19 PM, Jason W Kim wrote:
>
> 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;
Are these modifiers still being used? I don't see them.
Evan
>
> 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
> +
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
More information about the llvm-commits
mailing list