commit 5cfebdde2bf73e610146aff74067e538d5a89df3
author Jozef Kolek <jozef.kolek@imgtec.com> Wed Jan 21 12:39:30 2015 +0000
committer Jozef Kolek <jozef.kolek@imgtec.com> Wed Jan 21 12:39:30 2015 +0000
tree c3abbe7e682a08b288ce1851fb12d4bac5a92011
parent 2c6d73207ec948ed62433818e6ce197ca571c795

[mips][microMIPS] MicroMIPS 16-bit unconditional branch instruction B

Implement microMIPS 16-bit unconditional branch instruction B.

Implemented 16-bit microMIPS unconditional instruction has real name B16, and
B is an alias which expands to either B16 or BEQ according to the rules:
b 256 --> b16 256 # R_MICROMIPS_PC10_S1
b 12256 --> beq $zero, $zero, 12256 # R_MICROMIPS_PC16_S1
b label --> beq $zero, $zero, label # R_MICROMIPS_PC16_S1

Differential Revision: http://reviews.llvm.org/D3514

llvm-svn: 226657

llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp

diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
index 6670dc2..acf6f21 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -111,6 +111,14 @@
     if (!isIntN(7, Value) && Ctx)
       Ctx->FatalError(Fixup.getLoc(), "out of range PC7 fixup");
     break;
+  case Mips::fixup_MICROMIPS_PC10_S1:
+    Value -= 2;
+    // Forcing a signed division because Value can be negative.
+    Value = (int64_t) Value / 2;
+    // We now check if Value can be encoded as a 10-bit signed immediate.
+    if (!isIntN(10, Value) && Ctx)
+      Ctx->FatalError(Fixup.getLoc(), "out of range PC10 fixup");
+    break;
   case Mips::fixup_MICROMIPS_PC16_S1:
     Value -= 4;
     // Forcing a signed division because Value can be negative.
@@ -157,7 +165,8 @@
 //   microMIPS:  x | x | a | b
 
 static bool needsMMLEByteOrder(unsigned Kind) {
-  return Kind >= Mips::fixup_MICROMIPS_26_S1 &&
+  return Kind != Mips::fixup_MICROMIPS_PC10_S1 &&
+         Kind >= Mips::fixup_MICROMIPS_26_S1 &&
          Kind < Mips::LastTargetFixupKind;
 }
 
@@ -190,6 +199,7 @@
   switch ((unsigned)Kind) {
   case FK_Data_2:
   case Mips::fixup_Mips_16:
+  case Mips::fixup_MICROMIPS_PC10_S1:
     FullSize = 2;
     break;
   case FK_Data_8:
@@ -280,6 +290,7 @@
     { "fixup_MICROMIPS_LO16",    0,     16,   0 },
     { "fixup_MICROMIPS_GOT16",   0,     16,   0 },
     { "fixup_MICROMIPS_PC7_S1",  0,      7,   MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_MICROMIPS_PC10_S1", 0,     10,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_PC16_S1", 0,     16,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_CALL16",  0,     16,   0 },
     { "fixup_MICROMIPS_GOT_DISP",        0,     16,   0 },
@@ -344,6 +355,7 @@
     { "fixup_MICROMIPS_LO16",   16,     16,   0 },
     { "fixup_MICROMIPS_GOT16",  16,     16,   0 },
     { "fixup_MICROMIPS_PC7_S1",  9,      7,   MCFixupKindInfo::FKF_IsPCRel },
+    { "fixup_MICROMIPS_PC10_S1", 6,     10,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_PC16_S1",16,     16,   MCFixupKindInfo::FKF_IsPCRel },
     { "fixup_MICROMIPS_CALL16", 16,     16,   0 },
     { "fixup_MICROMIPS_GOT_DISP",        16,     16,   0 },