[llvm-branch-commits] [llvm] 058a8cd - [MC][ARM] Resolve some pcrel fixups at assembly time (PR44929)
Hans Wennborg via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Thu Feb 27 03:49:22 PST 2020
Author: Hans Wennborg
Date: 2020-02-27T12:44:06+01:00
New Revision: 058a8cd73f33ae7be7bef469c1b7c2d5fdaa4b24
URL: https://github.com/llvm/llvm-project/commit/058a8cd73f33ae7be7bef469c1b7c2d5fdaa4b24
DIFF: https://github.com/llvm/llvm-project/commit/058a8cd73f33ae7be7bef469c1b7c2d5fdaa4b24.diff
LOG: [MC][ARM] Resolve some pcrel fixups at assembly time (PR44929)
MC currently does not emit these relocation types, and lld does not
handle them. Add FKF_Constant as a work-around of some ARM code after
D72197. Eventually we probably should implement these relocation types.
By Fangrui Song!
Differential revision: https://reviews.llvm.org/D72892
(cherry picked from commit 2e24219d3cbfcb8c824c58872f97de0a2e94a7c8)
Added:
llvm/test/MC/ARM/pcrel-global.s
Modified:
llvm/include/llvm/MC/MCFixupKindInfo.h
llvm/lib/MC/MCAssembler.cpp
llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
llvm/test/MC/ARM/Windows/invalid-relocation.s
llvm/test/MC/MachO/ARM/bad-darwin-ARM-reloc.s
Removed:
################################################################################
diff --git a/llvm/include/llvm/MC/MCFixupKindInfo.h b/llvm/include/llvm/MC/MCFixupKindInfo.h
index 0d57441ce0dc..ecf85fa56931 100644
--- a/llvm/include/llvm/MC/MCFixupKindInfo.h
+++ b/llvm/include/llvm/MC/MCFixupKindInfo.h
@@ -22,7 +22,12 @@ struct MCFixupKindInfo {
FKF_IsAlignedDownTo32Bits = (1 << 1),
/// Should this fixup be evaluated in a target dependent manner?
- FKF_IsTarget = (1 << 2)
+ FKF_IsTarget = (1 << 2),
+
+ /// This fixup kind should be resolved if defined.
+ /// FIXME This is a workaround because we don't support certain ARM
+ /// relocation types. This flag should eventually be removed.
+ FKF_Constant = 1 << 3,
};
/// A target specific name for the fixup kind. The names will be unique for
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 75ec27975564..6f897edb5d60 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -224,6 +224,7 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
return getBackend().evaluateTargetFixup(*this, Layout, Fixup, DF, Target,
Value, WasForced);
+ unsigned FixupFlags = getBackendPtr()->getFixupKindInfo(Fixup.getKind()).Flags;
bool IsPCRel = getBackendPtr()->getFixupKindInfo(Fixup.getKind()).Flags &
MCFixupKindInfo::FKF_IsPCRel;
@@ -239,8 +240,9 @@ bool MCAssembler::evaluateFixup(const MCAsmLayout &Layout,
if (A->getKind() != MCSymbolRefExpr::VK_None || SA.isUndefined()) {
IsResolved = false;
} else if (auto *Writer = getWriterPtr()) {
- IsResolved = Writer->isSymbolRefDifferenceFullyResolvedImpl(
- *this, SA, *DF, false, true);
+ IsResolved = (FixupFlags & MCFixupKindInfo::FKF_Constant) ||
+ Writer->isSymbolRefDifferenceFullyResolvedImpl(
+ *this, SA, *DF, false, true);
}
}
} else {
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 6196881a9b8f..062d1d36c43c 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -55,31 +55,29 @@ Optional<MCFixupKind> ARMAsmBackend::getFixupKind(StringRef Name) const {
}
const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
+ unsigned IsPCRelConstant =
+ MCFixupKindInfo::FKF_IsPCRel | MCFixupKindInfo::FKF_Constant;
const static MCFixupKindInfo InfosLE[ARM::NumTargetFixupKinds] = {
// This table *must* be in the order that the fixup_* kinds are defined in
// ARMFixupKinds.h.
//
// Name Offset (bits) Size (bits) Flags
- {"fixup_arm_ldst_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_arm_ldst_pcrel_12", 0, 32, IsPCRelConstant},
{"fixup_t2_ldst_pcrel_12", 0, 32,
- MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
- {"fixup_arm_pcrel_10_unscaled", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
- {"fixup_arm_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_pcrel_10_unscaled", 0, 32, IsPCRelConstant},
+ {"fixup_arm_pcrel_10", 0, 32, IsPCRelConstant},
{"fixup_t2_pcrel_10", 0, 32,
MCFixupKindInfo::FKF_IsPCRel |
MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
{"fixup_arm_pcrel_9", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_t2_pcrel_9", 0, 32,
- MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
{"fixup_thumb_adr_pcrel_10", 0, 8,
- MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
- {"fixup_arm_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_adr_pcrel_12", 0, 32, IsPCRelConstant},
{"fixup_t2_adr_pcrel_12", 0, 32,
- MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
{"fixup_arm_condbranch", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_arm_uncondbranch", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
{"fixup_t2_condbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
diff --git a/llvm/test/MC/ARM/Windows/invalid-relocation.s b/llvm/test/MC/ARM/Windows/invalid-relocation.s
index c3e74e97634b..183fc29e7018 100644
--- a/llvm/test/MC/ARM/Windows/invalid-relocation.s
+++ b/llvm/test/MC/ARM/Windows/invalid-relocation.s
@@ -7,7 +7,6 @@
.endef
.global invalid_relocation
.thumb_func
-invalid_relocation:
adr r0, invalid_relocation+1
# CHECK: LLVM ERROR: unsupported relocation type: fixup_t2_adr_pcrel_12
diff --git a/llvm/test/MC/ARM/pcrel-global.s b/llvm/test/MC/ARM/pcrel-global.s
new file mode 100644
index 000000000000..cec6c1cb52f3
--- /dev/null
+++ b/llvm/test/MC/ARM/pcrel-global.s
@@ -0,0 +1,21 @@
+@ RUN: llvm-mc -filetype=obj -triple=armv7 %s -o %t
+@ RUN: llvm-readelf -r %t | FileCheck %s
+
+@ CHECK: There are no relocations in this file.
+.syntax unified
+
+.globl foo
+foo:
+ldrd r0, r1, foo @ arm_pcrel_10_unscaled
+vldr d0, foo @ arm_pcrel_10
+adr r2, foo @ arm_adr_pcrel_12
+ldr r0, foo @ arm_ldst_pcrel_12
+
+.thumb
+.thumb_func
+
+.globl bar
+bar:
+adr r0, bar @ thumb_adr_pcrel_10
+adr.w r0, bar @ t2_adr_pcrel_12
+ldr.w pc, bar @ t2_ldst_pcrel_12
diff --git a/llvm/test/MC/MachO/ARM/bad-darwin-ARM-reloc.s b/llvm/test/MC/MachO/ARM/bad-darwin-ARM-reloc.s
index ae4bc225dc5d..c60f8a853b6e 100644
--- a/llvm/test/MC/MachO/ARM/bad-darwin-ARM-reloc.s
+++ b/llvm/test/MC/MachO/ARM/bad-darwin-ARM-reloc.s
@@ -6,7 +6,6 @@
.section myseg, mysect
L___fcommon:
.word 0
-@ CHECK-ERROR: unsupported relocation on symbol
c:
.word a - b
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