diff options
| author | Jack Carter <jack.carter@imgtec.com> | 2013-03-22 00:29:10 +0000 |
|---|---|---|
| committer | Jack Carter <jack.carter@imgtec.com> | 2013-03-22 00:29:10 +0000 |
| commit | d3107fbc54a5b5156f0aabc8788724f1469eb9df (patch) | |
| tree | 33d629334f36d0d98f940190667609cc02388809 | |
| parent | 25df6a93f3324bd30f44dcb95fd17aff0a92d438 (diff) | |
Fix the invalid opcode for Mips branch instructions in the assembler
For mips a branch an 18-bit signed offset (the 16-bit
offset field shifted left 2 bits) is added to the
address of the instruction following the branch
(not the branch itself), in the branch delay slot,
to form a PC-relative effective target address.
Previously, the code generator did not perform the
shift of the immediate branch offset which resulted
in wrong instruction opcode. This patch fixes the issue.
Contributor: Vladimir Medic
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177687 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp | 10 | ||||
| -rw-r--r-- | test/MC/Mips/mips-jump-instructions.s | 24 |
2 files changed, 18 insertions, 16 deletions
diff --git a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp index 96f93a0789..e198a7c983 100644 --- a/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp +++ b/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp @@ -160,8 +160,9 @@ getBranchTargetOpValue(const MCInst &MI, unsigned OpNo, const MCOperand &MO = MI.getOperand(OpNo); - // If the destination is an immediate, we have nothing to do. - if (MO.isImm()) return MO.getImm(); + // If the destination is an immediate, divide by 4. + if (MO.isImm()) return MO.getImm() >> 2; + assert(MO.isExpr() && "getBranchTargetOpValue expects only expressions or immediates"); @@ -179,8 +180,9 @@ getJumpTargetOpValue(const MCInst &MI, unsigned OpNo, SmallVectorImpl<MCFixup> &Fixups) const { const MCOperand &MO = MI.getOperand(OpNo); - // If the destination is an immediate, we have nothing to do. - if (MO.isImm()) return MO.getImm(); + // If the destination is an immediate, divide by 4. + if (MO.isImm()) return MO.getImm()>>2; + assert(MO.isExpr() && "getJumpTargetOpValue expects only expressions or an immediate"); diff --git a/test/MC/Mips/mips-jump-instructions.s b/test/MC/Mips/mips-jump-instructions.s index bc2d720398..849eae9325 100644 --- a/test/MC/Mips/mips-jump-instructions.s +++ b/test/MC/Mips/mips-jump-instructions.s @@ -5,25 +5,25 @@ #------------------------------------------------------------------------------ # Branch instructions #------------------------------------------------------------------------------ -# CHECK: b 1332 # encoding: [0x34,0x05,0x00,0x10] +# CHECK: b 1332 # encoding: [0x4d,0x01,0x00,0x10] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bc1f 1332 # encoding: [0x34,0x05,0x00,0x45] +# CHECK: bc1f 1332 # encoding: [0x4d,0x01,0x00,0x45] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bc1t 1332 # encoding: [0x34,0x05,0x01,0x45] +# CHECK: bc1t 1332 # encoding: [0x4d,0x01,0x01,0x45] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: beq $9, $6, 1332 # encoding: [0x34,0x05,0x26,0x11] +# CHECK: beq $9, $6, 1332 # encoding: [0x4d,0x01,0x26,0x11] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bgez $6, 1332 # encoding: [0x34,0x05,0xc1,0x04] +# CHECK: bgez $6, 1332 # encoding: [0x4d,0x01,0xc1,0x04] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bgezal $6, 1332 # encoding: [0x34,0x05,0xd1,0x04] +# CHECK: bgezal $6, 1332 # encoding: [0x4d,0x01,0xd1,0x04] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bgtz $6, 1332 # encoding: [0x34,0x05,0xc0,0x1c] +# CHECK: bgtz $6, 1332 # encoding: [0x4d,0x01,0xc0,0x1c] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: blez $6, 1332 # encoding: [0x34,0x05,0xc0,0x18] +# CHECK: blez $6, 1332 # encoding: [0x4d,0x01,0xc0,0x18] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bne $9, $6, 1332 # encoding: [0x34,0x05,0x26,0x15] +# CHECK: bne $9, $6, 1332 # encoding: [0x4d,0x01,0x26,0x15] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: bal 1332 # encoding: [0x34,0x05,0x11,0x04] +# CHECK: bal 1332 # encoding: [0x4d,0x01,0x11,0x04] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] b 1332 nop @@ -50,9 +50,9 @@ end_of_code: #------------------------------------------------------------------------------ # Jump instructions #------------------------------------------------------------------------------ -# CHECK: j 1328 # encoding: [0x30,0x05,0x00,0x08] +# CHECK: j 1328 # encoding: [0x4c,0x01,0x00,0x08] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] -# CHECK: jal 1328 # encoding: [0x30,0x05,0x00,0x0c] +# CHECK: jal 1328 # encoding: [0x4c,0x01,0x00,0x0c] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] # CHECK: jalr $6 # encoding: [0x09,0xf8,0xc0,0x00] # CHECK: nop # encoding: [0x00,0x00,0x00,0x00] |