Disassembly of A8.6.59 LDR (literal) Encoding T1 (16-bit thumb instruction) should

print out ldr, not ldr.n.

rdar://problem/9267772

llvm-svn: 130008

4 files changed, 24 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb.td b/llvm/lib/Target/ARM/ARMInstrThumb.td
index 9c88c10315e..eab38272ecd 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb.td
@@ -721,6 +721,19 @@ def tLDRpci : T1pIs<(outs tGPR:$Rt), (ins t_addrmode_pc:$addr), IIC_iLoad_i,
   let Inst{7-0}  = addr;
 }
 
+// FIXME: Remove this entry when the above ldr.n workaround is fixed.
+// For disassembly use only.
+def tLDRpciDIS : T1pIs<(outs tGPR:$Rt), (ins t_addrmode_pc:$addr), IIC_iLoad_i,
+                       "ldr", "\t$Rt, $addr",
+                       [/* disassembly only */]>,
+                 T1Encoding<{0,1,0,0,1,?}> {
+  // A6.2 & A8.6.59
+  bits<3> Rt;
+  bits<8> addr;
+  let Inst{10-8} = Rt;
+  let Inst{7-0}  = addr;
+}
+
 // A8.6.194 & A8.6.192
 defm tSTR  : thumb_st_rr_ri_enc<0b000, 0b0110, t_addrmode_rrs4,
                                 t_addrmode_is4, AddrModeT1_4,
diff --git a/llvm/test/MC/Disassembler/ARM/thumb-printf.txt b/llvm/test/MC/Disassembler/ARM/thumb-printf.txt
index 09f54abf824..6c2c500630d 100644
--- a/llvm/test/MC/Disassembler/ARM/thumb-printf.txt
+++ b/llvm/test/MC/Disassembler/ARM/thumb-printf.txt
@@ -7,17 +7,17 @@
 # CHECK-NEXT:	add	r3, sp, #20
 # CHECK-NEXT:	ldr	r5, [r3], #4
 # CHECK-NEXT:	str	r3, [sp]
-# CHECK-NEXT:	ldr.n	r3, #52
+# CHECK-NEXT:	ldr	r3, #52
 # CHECK-NEXT:	add	r3, pc
 # CHECK-NEXT:	ldr	r0, [r3]
 # CHECK-NEXT:	ldr	r4, [r0]
-# CHECK-NEXT:	ldr.n	r0, #48
+# CHECK-NEXT:	ldr	r0, #48
 # CHECK-NEXT:	add	r0, pc
 # CHECK-NEXT:	ldr	r0, [r0]
 # CHECK-NEXT:	ldr	r0, [r0]
 # CHECK-NEXT:	blx	#191548
 # CHECK-NEXT:	cbnz	r0, #6
-# CHECK-NEXT:	ldr.n	r1, #40
+# CHECK-NEXT:	ldr	r1, #40
 # CHECK-NEXT:	add	r1, pc
 # CHECK-NEXT:	ldr	r1, [r1]
 # CHECK-NEXT:	b	#0
diff --git a/llvm/test/MC/Disassembler/ARM/thumb-tests.txt b/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
index 39030a8b376..2cbb33cec76 100644
--- a/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
+++ b/llvm/test/MC/Disassembler/ARM/thumb-tests.txt
@@ -30,6 +30,9 @@
 # CHECK:	ldmia	r0!, {r1}
 0x02 0xc8
 
+# CHECK:	ldr	r5, #432
+0x6c 0x4d
+
 # CHECK:	str	r0, [r3]
 0x18 0x60
 
diff --git a/llvm/utils/TableGen/ARMDecoderEmitter.cpp b/llvm/utils/TableGen/ARMDecoderEmitter.cpp
index ed44f821a20..62bd1c65e4b 100644
--- a/llvm/utils/TableGen/ARMDecoderEmitter.cpp
+++ b/llvm/utils/TableGen/ARMDecoderEmitter.cpp
@@ -1652,6 +1652,11 @@ ARMDEBackend::populateInstruction(const CodeGenInstruction &CGI,
         Name == "t2ADDrSPi12" || Name == "t2SUBrSPi12")
       return false;
 
+    // FIXME: Use ldr.n to work around a Darwin assembler bug.
+    // Introduce a workaround with tLDRpciDIS opcode.
+    if (Name == "tLDRpci")
+      return false;
+
     // Ignore t2LDRDpci, prefer the generic t2LDRDi8, t2LDRD_PRE, t2LDRD_POST.
     if (Name == "t2LDRDpci")
       return false;