Vendor import of llvm trunk r161861:

http://llvm.org/svn/llvm-project/llvm/trunk@161861

1 files changed, 111 insertions, 66 deletions

diff --git a/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index d10bfc1..ac6ce64 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -12,6 +12,7 @@
 #include "MCTargetDesc/ARMFixupKinds.h"
 #include "MCTargetDesc/ARMAddressingModes.h"
 #include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCELFObjectWriter.h"
 #include "llvm/MC/MCExpr.h"
@@ -84,7 +85,8 @@ public:
 { "fixup_arm_thumb_bl",      0,            32,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_arm_thumb_blx",     0,            32,  MCFixupKindInfo::FKF_IsPCRel },
 { "fixup_arm_thumb_cb",      0,            16,  MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_arm_thumb_cp",      0,             8,  MCFixupKindInfo::FKF_IsPCRel },
+{ "fixup_arm_thumb_cp",      0,             8,  MCFixupKindInfo::FKF_IsPCRel |
+                                   MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
 { "fixup_arm_thumb_bcc",     0,             8,  MCFixupKindInfo::FKF_IsPCRel },
 // movw / movt: 16-bits immediate but scattered into two chunks 0 - 12, 16 - 19.
 { "fixup_arm_movt_hi16",     0,            20,  0 },
@@ -110,32 +112,7 @@ public:
   void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
                          const MCFixup &Fixup, const MCFragment *DF,
                          MCValue &Target, uint64_t &Value,
-                         bool &IsResolved) {
-    const MCSymbolRefExpr *A = Target.getSymA();
-    // Some fixups to thumb function symbols need the low bit (thumb bit)
-    // twiddled.
-    if ((unsigned)Fixup.getKind() != ARM::fixup_arm_ldst_pcrel_12 &&
-        (unsigned)Fixup.getKind() != ARM::fixup_t2_ldst_pcrel_12 &&
-        (unsigned)Fixup.getKind() != ARM::fixup_arm_adr_pcrel_12 &&
-        (unsigned)Fixup.getKind() != ARM::fixup_thumb_adr_pcrel_10 &&
-        (unsigned)Fixup.getKind() != ARM::fixup_t2_adr_pcrel_12 &&
-        (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp) {
-      if (A) {
-        const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
-        if (Asm.isThumbFunc(&Sym))
-          Value |= 1;
-      }
-    }
-    // We must always generate a relocation for BL/BLX instructions if we have
-    // a symbol to reference, as the linker relies on knowing the destination
-    // symbol's thumb-ness to get interworking right.
-    if (A && ((unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_blx ||
-              (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl ||
-              (unsigned)Fixup.getKind() == ARM::fixup_arm_blx ||
-              (unsigned)Fixup.getKind() == ARM::fixup_arm_uncondbl ||
-              (unsigned)Fixup.getKind() == ARM::fixup_arm_condbl))
-      IsResolved = false;
-  }
+                         bool &IsResolved);
 
   bool mayNeedRelaxation(const MCInst &Inst) const;
 
@@ -269,7 +246,9 @@ bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
   return true;
 }
 
-static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
+static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
+                                 MCContext *Ctx = NULL) {
+  unsigned Kind = Fixup.getKind();
   switch (Kind) {
   default:
     llvm_unreachable("Unknown fixup kind!");
@@ -322,7 +301,8 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
       Value = -Value;
       isAdd = false;
     }
-    assert ((Value < 4096) && "Out of range pc-relative fixup value!");
+    if (Ctx && Value >= 4096)
+      Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
     Value |= isAdd << 23;
 
     // Same addressing mode as fixup_arm_pcrel_10,
@@ -345,8 +325,8 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
       Value = -Value;
       opc = 2; // 0b0010
     }
-    assert(ARM_AM::getSOImmVal(Value) != -1 &&
-           "Out of range pc-relative fixup value!");
+    if (Ctx && ARM_AM::getSOImmVal(Value) == -1)
+      Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
     // Encode the immediate and shift the opcode into place.
     return ARM_AM::getSOImmVal(Value) | (opc << 21);
   }
@@ -414,39 +394,65 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
     return swapped;
   }
   case ARM::fixup_arm_thumb_bl: {
-    // The value doesn't encode the low bit (always zero) and is offset by
-    // four. The value is encoded into disjoint bit positions in the destination
-    // opcode. x = unchanged, I = immediate value bit, S = sign extension bit
-    //
-    //   BL:  xxxxxSIIIIIIIIII xxxxxIIIIIIIIIII
-    //
-    // Note that the halfwords are stored high first, low second; so we need
-    // to transpose the fixup value here to map properly.
-    unsigned isNeg = (int64_t(Value - 4) < 0) ? 1 : 0;
-    uint32_t Binary = 0;
-    Value = 0x3fffff & ((Value - 4) >> 1);
-    Binary  = (Value & 0x7ff) << 16;    // Low imm11 value.
-    Binary |= (Value & 0x1ffc00) >> 11; // High imm10 value.
-    Binary |= isNeg << 10;              // Sign bit.
-    return Binary;
+     // The value doesn't encode the low bit (always zero) and is offset by
+     // four. The 32-bit immediate value is encoded as
+     //   imm32 = SignExtend(S:I1:I2:imm10:imm11:0)
+     // where I1 = NOT(J1 ^ S) and I2 = NOT(J2 ^ S).
+     // The value is encoded into disjoint bit positions in the destination
+     // opcode. x = unchanged, I = immediate value bit, S = sign extension bit,
+     // J = either J1 or J2 bit
+     //
+     //   BL:  xxxxxSIIIIIIIIII xxJxJIIIIIIIIIII
+     //
+     // Note that the halfwords are stored high first, low second; so we need
+     // to transpose the fixup value here to map properly.
+     uint32_t offset = (Value - 4) >> 1;
+     uint32_t signBit = (offset & 0x800000) >> 23;
+     uint32_t I1Bit = (offset & 0x400000) >> 22;
+     uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
+     uint32_t I2Bit = (offset & 0x200000) >> 21;
+     uint32_t J2Bit = (I2Bit ^ 0x1) ^ signBit;
+     uint32_t imm10Bits = (offset & 0x1FF800) >> 11;
+     uint32_t imm11Bits = (offset & 0x000007FF);
+ 
+     uint32_t Binary = 0;
+     uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
+     uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
+                           (uint16_t)imm11Bits);
+     Binary |= secondHalf << 16;
+     Binary |= firstHalf;
+     return Binary;
+
   }
   case ARM::fixup_arm_thumb_blx: {
-    // The value doesn't encode the low two bits (always zero) and is offset by
-    // four (see fixup_arm_thumb_cp). The value is encoded into disjoint bit
-    // positions in the destination opcode. x = unchanged, I = immediate value
-    // bit, S = sign extension bit, 0 = zero.
-    //
-    //   BLX: xxxxxSIIIIIIIIII xxxxxIIIIIIIIII0
-    //
-    // Note that the halfwords are stored high first, low second; so we need
-    // to transpose the fixup value here to map properly.
-    unsigned isNeg = (int64_t(Value-4) < 0) ? 1 : 0;
-    uint32_t Binary = 0;
-    Value = 0xfffff & ((Value - 2) >> 2);
-    Binary  = (Value & 0x3ff) << 17;    // Low imm10L value.
-    Binary |= (Value & 0xffc00) >> 10;  // High imm10H value.
-    Binary |= isNeg << 10;              // Sign bit.
-    return Binary;
+     // The value doesn't encode the low two bits (always zero) and is offset by
+     // four (see fixup_arm_thumb_cp). The 32-bit immediate value is encoded as
+     //   imm32 = SignExtend(S:I1:I2:imm10H:imm10L:00)
+     // where I1 = NOT(J1 ^ S) and I2 = NOT(J2 ^ S).
+     // The value is encoded into disjoint bit positions in the destination 
+     // opcode. x = unchanged, I = immediate value bit, S = sign extension bit, 
+     // J = either J1 or J2 bit, 0 = zero.
+     //
+     //   BLX: xxxxxSIIIIIIIIII xxJxJIIIIIIIIII0
+     //
+     // Note that the halfwords are stored high first, low second; so we need
+     // to transpose the fixup value here to map properly.
+     uint32_t offset = (Value - 2) >> 2;
+     uint32_t signBit = (offset & 0x400000) >> 22;
+     uint32_t I1Bit = (offset & 0x200000) >> 21;
+     uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
+     uint32_t I2Bit = (offset & 0x100000) >> 20;
+     uint32_t J2Bit = (I2Bit ^ 0x1) ^ signBit;
+     uint32_t imm10HBits = (offset & 0xFFC00) >> 10;
+     uint32_t imm10LBits = (offset & 0x3FF);
+ 
+     uint32_t Binary = 0;
+     uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
+     uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) | 
+                           ((uint16_t)imm10LBits) << 1);
+     Binary |= secondHalf << 16;
+     Binary |= firstHalf;
+     return Binary;
   }
   case ARM::fixup_arm_thumb_cp:
     // Offset by 4, and don't encode the low two bits. Two bytes of that
@@ -473,7 +479,8 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
       isAdd = false;
     }
     // The value has the low 4 bits encoded in [3:0] and the high 4 in [11:8].
-    assert ((Value < 256) && "Out of range pc-relative fixup value!");
+    if (Ctx && Value >= 256)
+      Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
     Value = (Value & 0xf) | ((Value & 0xf0) << 4);
     return Value | (isAdd << 23);
   }
@@ -491,7 +498,8 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
     }
     // These values don't encode the low two bits since they're always zero.
     Value >>= 2;
-    assert ((Value < 256) && "Out of range pc-relative fixup value!");
+    if (Ctx && Value >= 256)
+      Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
     Value |= isAdd << 23;
 
     // Same addressing mode as fixup_arm_pcrel_10, but with 16-bit halfwords
@@ -507,6 +515,43 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
   }
 }
 
+void ARMAsmBackend::processFixupValue(const MCAssembler &Asm,
+                                      const MCAsmLayout &Layout,
+                                      const MCFixup &Fixup,
+                                      const MCFragment *DF,
+                                      MCValue &Target, uint64_t &Value,
+                                      bool &IsResolved) {
+  const MCSymbolRefExpr *A = Target.getSymA();
+  // Some fixups to thumb function symbols need the low bit (thumb bit)
+  // twiddled.
+  if ((unsigned)Fixup.getKind() != ARM::fixup_arm_ldst_pcrel_12 &&
+      (unsigned)Fixup.getKind() != ARM::fixup_t2_ldst_pcrel_12 &&
+      (unsigned)Fixup.getKind() != ARM::fixup_arm_adr_pcrel_12 &&
+      (unsigned)Fixup.getKind() != ARM::fixup_thumb_adr_pcrel_10 &&
+      (unsigned)Fixup.getKind() != ARM::fixup_t2_adr_pcrel_12 &&
+      (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp) {
+    if (A) {
+      const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
+      if (Asm.isThumbFunc(&Sym))
+        Value |= 1;
+    }
+  }
+  // We must always generate a relocation for BL/BLX instructions if we have
+  // a symbol to reference, as the linker relies on knowing the destination
+  // symbol's thumb-ness to get interworking right.
+  if (A && ((unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_blx ||
+            (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl ||
+            (unsigned)Fixup.getKind() == ARM::fixup_arm_blx ||
+            (unsigned)Fixup.getKind() == ARM::fixup_arm_uncondbl ||
+            (unsigned)Fixup.getKind() == ARM::fixup_arm_condbl))
+    IsResolved = false;
+
+  // Try to get the encoded value for the fixup as-if we're mapping it into
+  // the instruction. This allows adjustFixupValue() to issue a diagnostic
+  // if the value aren't invalid.
+  (void)adjustFixupValue(Fixup, Value, &Asm.getContext());
+}
+
 namespace {
 
 // FIXME: This should be in a separate file.
@@ -530,7 +575,7 @@ public:
 void ELFARMAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
                                   unsigned DataSize, uint64_t Value) const {
   unsigned NumBytes = 4;        // FIXME: 2 for Thumb
-  Value = adjustFixupValue(Fixup.getKind(), Value);
+  Value = adjustFixupValue(Fixup, Value);
   if (!Value) return;           // Doesn't change encoding.
 
   unsigned Offset = Fixup.getOffset();
@@ -615,7 +660,7 @@ static unsigned getFixupKindNumBytes(unsigned Kind) {
 void DarwinARMAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
                                      unsigned DataSize, uint64_t Value) const {
   unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
-  Value = adjustFixupValue(Fixup.getKind(), Value);
+  Value = adjustFixupValue(Fixup, Value);
   if (!Value) return;           // Doesn't change encoding.
 
   unsigned Offset = Fixup.getOffset();