Implement cleanups suggested by Daniel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121875 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/MC/MCCodeEmitter.h b/include/llvm/MC/MCCodeEmitter.h
index 2588661b62a802317c251a3dc78569382f7f69b5..d4eec7169e6685ca57cdbda8b92d28d74d18e2d5 100644 (file)
--- a/include/llvm/MC/MCCodeEmitter.h
+++ b/include/llvm/MC/MCCodeEmitter.h
@@ -27,8 +27,8 @@ struct MCFixupKindInfo {
     /// evaluate fixup values in a target independent manner when possible.
     FKF_IsPCRel = (1 << 0),
     
-    // Should this fixup kind force a 4-byte aligned effective PC value?
-    FKF_IsAligned = (1 << 1)
+    /// Should this fixup kind force a 4-byte aligned effective PC value?
+    FKF_IsAlignedDownTo32Bits = (1 << 1)
   };
 
   /// A target specific name for the fixup kind. The names will be unique for

diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 0fbd77c7f12853b98fd269557816d4f3f7ac91ec..0d114fb73148db8cf890594a4a8536001076b450 100644 (file)
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -248,14 +248,18 @@ bool MCAssembler::EvaluateFixup(const MCObjectWriter &Writer,
   if (IsResolved)
     IsResolved = Writer.IsFixupFullyResolved(*this, Target, IsPCRel, DF);
 
+  bool ShouldAlignPC = Emitter.getFixupKindInfo(Fixup.getKind()).Flags &
+                         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits;
+  assert((ShouldAlignPC ? IsPCRel : true) &&
+    "FKF_IsAlignedDownTo32Bits is only allowed on PC-relative fixups!");
+
   if (IsPCRel) {
-    bool ShouldAlignPC = Emitter.getFixupKindInfo(
-                        Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsAligned;
-    // PC should be aligned to a 4-byte value.
-    if (ShouldAlignPC)
-      Value -= Layout.getFragmentOffset(DF) + (Fixup.getOffset() & ~0x3);
-    else
-      Value -= Layout.getFragmentOffset(DF) + Fixup.getOffset();
+    uint32_t Offset = Fixup.getOffset();
+    
+    // A number of ARM fixups in Thumb mode require that the effective PC
+    // address be determined as the 32-bit aligned version of the actual offset.
+    if (ShouldAlignPC) Offset &= 0x3;
+    Value -= Layout.getFragmentOffset(DF) + Offset;
   }
 
   // ARM fixups based from a thumb function address need to have the low

diff --git a/lib/Target/ARM/ARMMCCodeEmitter.cpp b/lib/Target/ARM/ARMMCCodeEmitter.cpp
index db68f359a2c713f36d1d7f36da9313e830d8812c..1efcae03a4f7aea9f8a6daa9d104f1068fc7d8d2 100644 (file)
--- a/lib/Target/ARM/ARMMCCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMMCCodeEmitter.cpp
@@ -51,15 +51,15 @@ public:
 // Name                      Offset (bits) Size (bits)     Flags
 { "fixup_arm_ldst_pcrel_12", 1,            24,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_t2_ldst_pcrel_12",  0,            32,  MCFixupKindInfo::FKF_IsPCRel |
-                                                MCFixupKindInfo::FKF_IsAligned},
+                                   MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
 { "fixup_arm_pcrel_10",      1,            24,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_t2_pcrel_10",       0,            32,  MCFixupKindInfo::FKF_IsPCRel |
-                                                MCFixupKindInfo::FKF_IsAligned},
+                                   MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
 { "fixup_thumb_adr_pcrel_10",0,            8,   MCFixupKindInfo::FKF_IsPCRel |
-                                                MCFixupKindInfo::FKF_IsAligned},
+                                   MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
 { "fixup_arm_adr_pcrel_12",  1,            24,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_t2_adr_pcrel_12",   0,            32,  MCFixupKindInfo::FKF_IsPCRel |
-                                                MCFixupKindInfo::FKF_IsAligned},
+                                   MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
 { "fixup_arm_branch",        0,            24,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_t2_condbranch",     0,            32,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_t2_uncondbranch",   0,            32,  MCFixupKindInfo::FKF_IsPCRel },