[llvm] r235024 - Fix BXJ is undefined in AArch32.

[Charlie Turner]

Author: chatur01
Date: Wed Apr 15 12:28:23 2015
New Revision: 235024

URL: http://llvm.org/viewvc/llvm-project?rev=235024&view=rev
Log:
Fix BXJ is undefined in AArch32.

BXJ was incorrectly said to be unsupported in ARMv8-A. It is not
supported in the A64 instruction set, but it is supported in the T32
and A32 instruction sets, because it's listed as an instruction in the
ARM ARM section F7.1.28.

Using SP as an operand to BXJ changed from UNPREDICTABLE to
PREDICTABLE in v8-A. This patch reflects that update as well.

This was found by MCHammer.

Added:
    llvm/trunk/test/MC/ARM/thumb2-bxj-v8.s
Modified:
    llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
    llvm/trunk/test/MC/ARM/thumb2-bxj.s

Modified: llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td?rev=235024&r1=235023&r2=235024&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td (original)
+++ llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td Wed Apr 15 12:28:23 2015
@@ -3630,8 +3630,8 @@ def t2IT : Thumb2XI<(outs), (ins it_pred
 
 // Branch and Exchange Jazelle -- for disassembly only
 // Rm = Inst{19-16}
-def t2BXJ : T2I<(outs), (ins rGPR:$func), NoItinerary, "bxj", "\t$func", []>,
-    Sched<[WriteBr]>, Requires<[IsThumb2, IsNotMClass, PreV8]> {
+def t2BXJ : T2I<(outs), (ins GPRnopc:$func), NoItinerary, "bxj", "\t$func", []>,
+    Sched<[WriteBr]>, Requires<[IsThumb2, IsNotMClass]> {
   bits<4> func;
   let Inst{31-27} = 0b11110;
   let Inst{26} = 0;

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=235024&r1=235023&r2=235024&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Wed Apr 15 12:28:23 2015
@@ -6150,6 +6150,14 @@ bool ARMAsmParser::validateInstruction(M
                    "destination operands can't be identical");
     return false;
   }
+  case ARM::t2BXJ: {
+    const unsigned RmReg = Inst.getOperand(0).getReg();
+    // Rm = SP is no longer unpredictable in v8-A
+    if (RmReg == ARM::SP && !hasV8Ops())
+      return Error(Operands[2]->getStartLoc(),
+                   "r13 (SP) is an unpredictable operand to BXJ");
+    return false;
+  }
   case ARM::STRD: {
     // Rt2 must be Rt + 1.
     unsigned Rt = MRI->getEncodingValue(Inst.getOperand(0).getReg());

Added: llvm/trunk/test/MC/ARM/thumb2-bxj-v8.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/thumb2-bxj-v8.s?rev=235024&view=auto
==============================================================================
--- llvm/trunk/test/MC/ARM/thumb2-bxj-v8.s (added)
+++ llvm/trunk/test/MC/ARM/thumb2-bxj-v8.s Wed Apr 15 12:28:23 2015
@@ -0,0 +1,11 @@
+@ RUN: not llvm-mc -triple=thumbv6t2--none-eabi -show-encoding < %s 2>&1 | FileCheck %s --check-prefix=UNDEF
+@ RUN: not llvm-mc -triple=thumbv7a--none-eabi -show-encoding < %s 2>&1  | FileCheck %s --check-prefix=UNDEF
+@ RUN: not llvm-mc -triple=thumbv7r--none-eabi -show-encoding < %s 2>&1  | FileCheck %s --check-prefix=UNDEF
+@ RUN: not llvm-mc -triple=thumbv7m--none-eabi -show-encoding < %s 2>&1  | FileCheck %s --check-prefix=ARM_MODE
+@ RUN: llvm-mc -triple=thumbv8a--none-eabi -show-encoding < %s 2>&1  | FileCheck %s
+
+bxj r13
+
+@ CHECK: bxj	sp                      @ encoding: [0xcd,0xf3,0x00,0x8f]
+@ UNDEF:  error: r13 (SP) is an unpredictable operand to BXJ
+@ ARM_MODE: error: instruction requires: arm-mode

Modified: llvm/trunk/test/MC/ARM/thumb2-bxj.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/ARM/thumb2-bxj.s?rev=235024&r1=235023&r2=235024&view=diff
==============================================================================
--- llvm/trunk/test/MC/ARM/thumb2-bxj.s (original)
+++ llvm/trunk/test/MC/ARM/thumb2-bxj.s Wed Apr 15 12:28:23 2015
@@ -1,8 +1,8 @@
 @ RUN: llvm-mc -triple=thumbv6t2--none-eabi -show-encoding < %s | FileCheck %s
 @ RUN: llvm-mc -triple=thumbv7a--none-eabi -show-encoding < %s | FileCheck %s
 @ RUN: llvm-mc -triple=thumbv7r--none-eabi -show-encoding < %s | FileCheck %s
+@ RUN: llvm-mc -triple=thumbv8a--none-eabi -show-encoding < %s | FileCheck %s
 @ RUN: not llvm-mc -triple=thumbv7m--none-eabi -show-encoding < %s 2>&1 | FileCheck %s --check-prefix=UNDEF
-@ RUN: not llvm-mc -triple=thumbv8a--none-eabi -show-encoding < %s 2>&1 | FileCheck %s --check-prefix=UNDEF
 
         bxj r2