Support clrex on ARMv6K

[andrew]

Summary

The ARM clrex instruction was added to armv6k so enable it there.

This is needed by FreeBSD as, when targeting ARMv6, we require armv6k, and make use of the clrex instruction.

[rengolin]

Apart from the nit comment, LGTM. Thanks!

test/MC/ARM/arm11-hint-instr.s

8

Does this work with just -triple=thumbv6k, instead of using -mcpu?

[andrew]

test/MC/ARM/arm11-hint-instr.s

8

No, because 1. the nop instruction is changed to a mov r8, r8 with different encoding, and 2. complains the further instructions need either armv6m or armv6t2:

<stdin>:21:9: error: instruction requires: armv6m or armv6t2
        yield
        ^

[rengolin]

test/MC/ARM/arm11-hint-instr.s

8

Sounds like it wasn't meant to be that, anyway. We can fix that later, though. Feel free to commit.

[andrew]

Committed at rL256505

lib/Target/ARM/ARMInstrInfo.td

def STLEXD : AIstlex<0b01, (outs GPR:$Rd),
                     (ins GPRPairOp:$Rt, addr_offset_none:$addr),
                     NoItinerary, "stlexd", "\t$Rd, $Rt, $addr", []> {
   let DecoderMethod = "DecodeDoubleRegStore";
 }
 }
 
 def CLREX : AXI<(outs), (ins), MiscFrm, NoItinerary, "clrex",
                 [(int_arm_clrex)]>,
-            Requires<[IsARM, HasV7]>  {
+            Requires<[IsARM, HasV6K]>  {
   let Inst{31-0} = 0b11110101011111111111000000011111;
 }
 
 def : ARMPat<(strex_1 (and GPR:$Rt, 0xff), addr_offset_none:$addr),
              (STREXB GPR:$Rt, addr_offset_none:$addr)>;
 def : ARMPat<(strex_2 (and GPR:$Rt, 0xffff), addr_offset_none:$addr),
              (STREXH GPR:$Rt, addr_offset_none:$addr)>;
 

test/MC/ARM/arm11-hint-instr.s

 @ RUN: not llvm-mc -triple=armv6 -show-encoding < %s > %t1 2> %t2
 @ RUN: FileCheck --check-prefix=CHECK-V6 %s < %t1
 @ RUN: FileCheck --check-prefix=CHECK-ERROR-V6 %s < %t2
 @ RUN: llvm-mc -triple=armv6k -show-encoding < %s \
 @ RUN:     | FileCheck --check-prefix=CHECK-ARM %s
 @ RUN: llvm-mc -triple=armv6t2 -show-encoding < %s \
 @ RUN:     | FileCheck --check-prefix=CHECK-ARM %s
-@ RUN: llvm-mc -triple=thumb -mcpu=arm1156t2-s -show-encoding < %s \
-@ RUN:     | FileCheck --check-prefix=CHECK-THUMB %s
-@ RUN: llvm-mc -triple=armv6m -show-encoding < %s \
-@ RUN:     | FileCheck --check-prefix=CHECK-V6M %s
+@ RUN: not llvm-mc -triple=thumb -mcpu=arm1156t2-s -show-encoding < %s > %t3 2> %t4
+@ RUN: FileCheck --check-prefix=CHECK-THUMB %s < %t3
+@ RUN: FileCheck --check-prefix=CHECK-ERROR-THUMB %s < %t4
+@ RUN: not llvm-mc -triple=armv6m -show-encoding < %s > %t5 2> %t6
+@ RUN: FileCheck --check-prefix=CHECK-V6M %s < %t5
+@ RUN: FileCheck --check-prefix=CHECK-ERROR-V6M %s < %t6
 
   .syntax unified
 
 @------------------------------------------------------------------------------
-@ YIELD/WFE/WFI/SEV - are not supported pre v6K
+@ YIELD/WFE/WFI/SEV/CLREX - are not supported pre v6K
 @------------------------------------------------------------------------------
         nop
         yield
         wfe
         wfi
         sev
+        clrex
 
 
 @------------------------------------------------------------------------------
 @ v6 using ARM encoding
 @------------------------------------------------------------------------------
 @ CHECK-V6: mov  r0, r0                  @ encoding: [0x00,0x00,0xa0,0xe1]
 @ CHECK-ERROR-V6: error: instruction requires: armv6k
 @ CHECK-ERROR-V6: yield
 @ CHECK-ERROR-V6: ^
 @ CHECK-ERROR-V6: error: instruction requires: armv6k
 @ CHECK-ERROR-V6: wfe
 @ CHECK-ERROR-V6: ^
 @ CHECK-ERROR-V6: error: instruction requires: armv6k
 @ CHECK-ERROR-V6: wfi
 @ CHECK-ERROR-V6: error: instruction requires: armv6k
 @ CHECK-ERROR-V6: sev
 @ CHECK-ERROR-V6: ^
+@ CHECK-ERROR-V6: error: instruction requires: armv6k
+@ CHECK-ERROR-V6: clrex
+@ CHECK-ERROR-V6: ^
 
 @------------------------------------------------------------------------------
 @ v6K using ARM encoding
 @------------------------------------------------------------------------------
 @------------------------------------------------------------------------------
 @ v6T2 using ARM encoding (arm triple)
 @------------------------------------------------------------------------------
 @ CHECK-ARM: nop                             @ encoding: [0x00,0xf0,0x20,0xe3]
 @ CHECK-ARM: yield                           @ encoding: [0x01,0xf0,0x20,0xe3]
 @ CHECK-ARM: wfe                             @ encoding: [0x02,0xf0,0x20,0xe3]
 @ CHECK-ARM: wfi                             @ encoding: [0x03,0xf0,0x20,0xe3]
 @ CHECK-ARM: sev                             @ encoding: [0x04,0xf0,0x20,0xe3]
+@ CHECK-ARM: clrex                           @ encoding: [0x1f,0xf0,0x7f,0xf5]
 
 @------------------------------------------------------------------------------
 @ v6T2 using THUMB encoding (thumb triple)
 @------------------------------------------------------------------------------
 @ CHECK-THUMB: nop                             @ encoding: [0x00,0xbf]
 @ CHECK-THUMB: yield                           @ encoding: [0x10,0xbf]
 @ CHECK-THUMB: wfe                             @ encoding: [0x20,0xbf]
 @ CHECK-THUMB: wfi                             @ encoding: [0x30,0xbf]
 @ CHECK-THUMB: sev                             @ encoding: [0x40,0xbf]
+@ CHECK-ERROR-THUMB: error: instruction requires: armv7
+@ CHECK-ERROR-THUMB: clrex
+@ CHECK-ERROR-THUMB: ^
 
 @------------------------------------------------------------------------------
 @ v6M using THUMB encoding
 @------------------------------------------------------------------------------
 @ CHECK-V6M: nop                             @ encoding: [0x00,0xbf]
 @ CHECK-V6M: yield                           @ encoding: [0x10,0xbf]
 @ CHECK-V6M: wfe                             @ encoding: [0x20,0xbf]
 @ CHECK-V6M: wfi                             @ encoding: [0x30,0xbf]
 @ CHECK-V6M: sev                             @ encoding: [0x40,0xbf]
+@ CHECK-ERROR-V6M: error: instruction requires: armv7
+@ CHECK-ERROR-V6M: clrex
+@ CHECK-ERROR-V6M: ^