Mips specific llvm assembler support for branch and jump instructions.

Test case included.

Contributer: Vladimir Medic

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163277 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index 8dab62d518135f9c69e1b454b7fc9da691c4468f..1d7370a04f1da3294542106e9ef6a4a719996b73 100644 (file)
--- a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -143,7 +143,11 @@ getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
                        SmallVectorImpl<MCFixup> &Fixups) const {
 
   const MCOperand &MO = MI.getOperand(OpNo);
-  assert(MO.isExpr() && "getBranchTargetOpValue expects only expressions");
+
+  // If the destination is an immediate, we have nothing to do.
+  if (MO.isImm()) return MO.getImm();
+  assert(MO.isExpr() &&
+         "getBranchTargetOpValue expects only expressions or immediates");
 
   const MCExpr *Expr = MO.getExpr();
   Fixups.push_back(MCFixup::Create(0, Expr,
@@ -159,7 +163,10 @@ getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
                      SmallVectorImpl<MCFixup> &Fixups) const {
 
   const MCOperand &MO = MI.getOperand(OpNo);
-  assert(MO.isExpr() && "getJumpTargetOpValue expects only expressions");
+  // If the destination is an immediate, we have nothing to do.
+  if (MO.isImm()) return MO.getImm();
+  assert(MO.isExpr() &&
+         "getJumpTargetOpValue expects only expressions or an immediate");
 
   const MCExpr *Expr = MO.getExpr();
   Fixups.push_back(MCFixup::Create(0, Expr,

diff --git a/test/MC/Mips/mips-jump-instructions.s b/test/MC/Mips/mips-jump-instructions.s
new file mode 100644 (file)
index 0000000..5188751
--- /dev/null
+++ b/test/MC/Mips/mips-jump-instructions.s
@@ -0,0 +1,64 @@
+# RUN: llvm-mc %s -triple=mipsel-unknown-linux -show-encoding -mcpu=mips32r2 | FileCheck %s
+# Check that the assembler can handle the documented syntax
+# for jumps and branches.
+# CHECK: .section __TEXT,__text,regular,pure_instructions
+#------------------------------------------------------------------------------
+# Branch instructions
+#------------------------------------------------------------------------------
+# CHECK:   b 1332                 # encoding: [0x34,0x05,0x00,0x10]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bc1f 1332              # encoding: [0x34,0x05,0x00,0x45]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bc1t 1332              # encoding: [0x34,0x05,0x01,0x45]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   beq $9, $6, 1332       # encoding: [0x34,0x05,0x26,0x11]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bgez $6, 1332          # encoding: [0x34,0x05,0xc1,0x04]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bgezal $6, 1332        # encoding: [0x34,0x05,0xd1,0x04]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bgtz $6, 1332          # encoding: [0x34,0x05,0xc0,0x1c]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   blez $6, 1332          # encoding: [0x34,0x05,0xc0,0x18]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   bne $9, $6, 1332       # encoding: [0x34,0x05,0x26,0x15]
+# CHECK:   nop                    # encoding: [0x00,0x00,0x00,0x00]
+         b 1332
+         nop
+         bc1f 1332
+         nop
+         bc1t 1332
+         nop
+         beq $9,$6,1332
+         nop
+         bgez $6,1332
+         nop
+         bgezal $6,1332
+         nop
+         bgtz $6,1332
+         nop
+         blez $6,1332
+         nop
+         bne $9,$6,1332
+         nop
+
+end_of_code:
+#------------------------------------------------------------------------------
+# Jump instructions
+#------------------------------------------------------------------------------
+# CHECK:   j 1328               # encoding: [0x30,0x05,0x00,0x08]
+# CHECK:   nop                  # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   jal 1328             # encoding: [0x30,0x05,0x00,0x0c]
+# CHECK:   nop                  # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   jalr $6              # encoding: [0x09,0xf8,0xc0,0x00]
+# CHECK:   nop                  # encoding: [0x00,0x00,0x00,0x00]
+# CHECK:   jr $7                # encoding: [0x08,0x00,0xe0,0x00]
+
+
+   j 1328
+   nop
+   jal 1328
+   nop
+   jalr $6
+   nop
+   jr $7