From d535cd7ed523edb92707cb835c8b488ae51e1be6 Mon Sep 17 00:00:00 2001
From: Stepan Dyatkovskiy <stpworld@narod.ru>
Date: Thu, 3 Apr 2014 11:29:15 +0000
Subject: [PATCH] PR19320: The trouble as in ARMAsmParser, in ParseInstruction
 method. It assumes that ARM::R12 + 1 == ARM::SP. It is wrong, since
 ARM::<Register> codes are generated by tablegen and actually could be any
 random numbers.

llvm-svn: 205524
---
 lib/Target/ARM/AsmParser/ARMAsmParser.cpp | 13 +++++++++----
 test/MC/ARM/ldrd-strd-gnu-sp.s            |  9 +++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)
 create mode 100644 test/MC/ARM/ldrd-strd-gnu-sp.s

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 8372f05c598..9c57a244fdb 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5408,11 +5408,16 @@ bool ARMAsmParser::ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
       Operands.size() == 4) {
     ARMOperand *Op = static_cast<ARMOperand *>(Operands[2]);
     assert(Op->isReg() && "expected register argument");
-    assert(MRI->getMatchingSuperReg(Op->getReg(), ARM::gsub_0,
-                                    &MRI->getRegClass(ARM::GPRPairRegClassID))
-           && "expected register pair");
+
+    unsigned SuperReg = MRI->getMatchingSuperReg(
+        Op->getReg(), ARM::gsub_0, &MRI->getRegClass(ARM::GPRPairRegClassID));
+
+    assert(SuperReg && "expected register pair");
+
+    unsigned PairedReg = MRI->getSubReg(SuperReg, ARM::gsub_1);
+
     Operands.insert(Operands.begin() + 3,
-                    ARMOperand::CreateReg(Op->getReg() + 1, Op->getStartLoc(),
+                    ARMOperand::CreateReg(PairedReg, Op->getStartLoc(),
                                           Op->getEndLoc()));
   }
 
diff --git a/test/MC/ARM/ldrd-strd-gnu-sp.s b/test/MC/ARM/ldrd-strd-gnu-sp.s
new file mode 100644
index 00000000000..21efae98525
--- /dev/null
+++ b/test/MC/ARM/ldrd-strd-gnu-sp.s
@@ -0,0 +1,9 @@
+// PR19320
+// RUN: llvm-mc -triple=armv7-linux-gnueabi -show-encoding < %s | FileCheck %s
+.text
+
+// CHECK: ldrd	r12, sp, [r0, #32]      @ encoding: [0xd0,0xc2,0xc0,0xe1]
+        ldrd    r12, [r0, #32]
+
+// CHECK: strd	r12, sp, [r0, #32]      @ encoding: [0xf0,0xc2,0xc0,0xe1]
+        strd    r12, [r0, #32]