Make sure the alternate PC+imm syntax of LDR instruction with a small

immediate generates the narrow version.  Needed when doing round-trip
assemble/disassemble testing using the alternate syntax that specifies
'pc' directly.

llvm-svn: 170255

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 4685b1d..6b42239 100644 (file)
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5723,7 +5723,12 @@ processInstruction(MCInst &Inst,
   }
   // Aliases for alternate PC+imm syntax of LDR instructions.
   case ARM::t2LDRpcrel:
-    Inst.setOpcode(ARM::t2LDRpci);
+    // Select the narrow version if the immediate will fit.
+    if (Inst.getOperand(1).getImm() > 0 &&
+        Inst.getOperand(1).getImm() <= 0xff)
+      Inst.setOpcode(ARM::tLDRpci);
+    else
+      Inst.setOpcode(ARM::t2LDRpci);
     return true;
   case ARM::t2LDRBpcrel:
     Inst.setOpcode(ARM::t2LDRBpci);

diff --git a/llvm/test/MC/ARM/basic-thumb2-instructions.s b/llvm/test/MC/ARM/basic-thumb2-instructions.s
index 23d9f59..d495c91 100644 (file)
--- a/llvm/test/MC/ARM/basic-thumb2-instructions.s
+++ b/llvm/test/MC/ARM/basic-thumb2-instructions.s
@@ -3509,3 +3509,7 @@ _func:
 @ CHECK: ldrh.w        r11, [pc, #-22]         @ encoding: [0x3f,0xf8,0x16,0xb0]
 @ CHECK: ldrsb.w r11, [pc, #-22]        @ encoding: [0x1f,0xf9,0x16,0xb0]
 @ CHECK: ldrsh.w r11, [pc, #-22]        @ encoding: [0x3f,0xf9,0x16,0xb0]
+
+@ rdar://12596361
+        ldr r1, [pc, #12]
+@ CHECK: ldr.n r1, [pc, #12]        @ encoding: [0x03,0x49]