From 33470a73f0a82566e565614e2017b2ecff5f55cd Mon Sep 17 00:00:00 2001
From: Jim Grosbach <grosbach@apple.com>
Date: Tue, 28 Jun 2011 00:19:13 +0000
Subject: [PATCH] ARM Thumb2 asm syntax optional destination operand for binary
 operators.

When the destination operand is the same as the first source register
operand for arithmetic instructions, the destination operand may be omitted.

For example, the following two instructions are equivalent:
and r1, #ff
and r1, r1, #ff

rdar://9672867

llvm-svn: 133973
---
 lib/Target/ARM/ARMInstrThumb2.td | 38 ++++++++++++++++++++++++--------
 test/MC/ARM/thumb2.s             | 20 +++++++++++++++++
 2 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index f36a49e9434..06c63e39377 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -465,7 +465,8 @@ multiclass T2I_un_irs<bits<4> opcod, string opc,
 /// changed to modify CPSR.
 multiclass T2I_bin_irs<bits<4> opcod, string opc,
                      InstrItinClass iii, InstrItinClass iir, InstrItinClass iis,
-                       PatFrag opnode, bit Commutable = 0, string wide = ""> {
+                       PatFrag opnode, string baseOpc, bit Commutable = 0,
+                       string wide = ""> {
    // shifted imm
    def ri : T2sTwoRegImm<
                 (outs rGPR:$Rd), (ins rGPR:$Rn, t2_so_imm:$imm), iii,
@@ -497,14 +498,31 @@ multiclass T2I_bin_irs<bits<4> opcod, string opc,
      let Inst{26-25} = 0b01;
      let Inst{24-21} = opcod;
    }
+  // Assembly aliases for optional destination operand when it's the same
+  // as the source operand.
+  def : InstAlias<!strconcat(opc, "${s}${p} $Rdn, $imm"),
+     (!cast<Instruction>(!strconcat(baseOpc, "ri")) rGPR:$Rdn, rGPR:$Rdn,
+                                                    t2_so_imm:$imm, pred:$p,
+                                                    cc_out:$s)>,
+     Requires<[IsThumb2]>;
+  def : InstAlias<!strconcat(opc, "${s}${p}", wide, " $Rdn, $Rm"),
+     (!cast<Instruction>(!strconcat(baseOpc, "rr")) rGPR:$Rdn, rGPR:$Rdn,
+                                                    rGPR:$Rm, pred:$p,
+                                                    cc_out:$s)>,
+     Requires<[IsThumb2]>;
+  def : InstAlias<!strconcat(opc, "${s}${p}", wide, " $Rdn, $shift"),
+     (!cast<Instruction>(!strconcat(baseOpc, "rs")) rGPR:$Rdn, rGPR:$Rdn,
+                                                    t2_so_reg:$shift, pred:$p,
+                                                    cc_out:$s)>,
+     Requires<[IsThumb2]>;
 }
 
 /// T2I_bin_w_irs - Same as T2I_bin_irs except these operations need
-//  the ".w" prefix to indicate that they are wide.
+//  the ".w" suffix to indicate that they are wide.
 multiclass T2I_bin_w_irs<bits<4> opcod, string opc,
                      InstrItinClass iii, InstrItinClass iir, InstrItinClass iis,
-                         PatFrag opnode, bit Commutable = 0> :
-    T2I_bin_irs<opcod, opc, iii, iir, iis, opnode, Commutable, ".w">;
+                         PatFrag opnode, string baseOpc, bit Commutable = 0> :
+    T2I_bin_irs<opcod, opc, iii, iir, iis, opnode, baseOpc, Commutable, ".w">;
 
 /// T2I_rbin_is - Same as T2I_bin_irs except the order of operands are
 /// reversed.  The 'rr' form is only defined for the disassembler; for codegen
@@ -2069,17 +2087,18 @@ def t2MOVsra_flag : T2TwoRegShiftImm<
 
 defm t2AND  : T2I_bin_w_irs<0b0000, "and",
                             IIC_iBITi, IIC_iBITr, IIC_iBITsi,
-                            BinOpFrag<(and node:$LHS, node:$RHS)>, 1>;
+                            BinOpFrag<(and node:$LHS, node:$RHS)>, "t2AND", 1>;
 defm t2ORR  : T2I_bin_w_irs<0b0010, "orr",
                             IIC_iBITi, IIC_iBITr, IIC_iBITsi,
-                            BinOpFrag<(or  node:$LHS, node:$RHS)>, 1>;
+                            BinOpFrag<(or  node:$LHS, node:$RHS)>, "t2ORR", 1>;
 defm t2EOR  : T2I_bin_w_irs<0b0100, "eor",
                             IIC_iBITi, IIC_iBITr, IIC_iBITsi,
-                            BinOpFrag<(xor node:$LHS, node:$RHS)>, 1>;
+                            BinOpFrag<(xor node:$LHS, node:$RHS)>, "t2EOR", 1>;
 
 defm t2BIC  : T2I_bin_w_irs<0b0001, "bic",
                             IIC_iBITi, IIC_iBITr, IIC_iBITsi,
-                            BinOpFrag<(and node:$LHS, (not node:$RHS))>>;
+                            BinOpFrag<(and node:$LHS, (not node:$RHS))>,
+                            "t2BIC">;
 
 class T2BitFI<dag oops, dag iops, InstrItinClass itin,
               string opc, string asm, list<dag> pattern>
@@ -2179,7 +2198,8 @@ let Constraints = "$src = $Rd" in {
 
 defm t2ORN  : T2I_bin_irs<0b0011, "orn",
                           IIC_iBITi, IIC_iBITr, IIC_iBITsi,
-                          BinOpFrag<(or  node:$LHS, (not node:$RHS))>, 0, "">;
+                          BinOpFrag<(or  node:$LHS, (not node:$RHS))>,
+                          "t2ORN", 0, "">;
 
 // Prefer over of t2EORri ra, rb, -1 because mvn has 16-bit version
 let AddedComplexity = 1 in
diff --git a/test/MC/ARM/thumb2.s b/test/MC/ARM/thumb2.s
index 1a268a970c5..41dda84d3f2 100644
--- a/test/MC/ARM/thumb2.s
+++ b/test/MC/ARM/thumb2.s
@@ -318,3 +318,23 @@
   ldrexd  r0, r1, [r0]
 @ CHECK: ssat16  r0, #7, r0 @ encoding: [0x20,0xf3,0x06,0x00]
   ssat16  r0, #7, r0
+
+  and r1, #0xff
+  and r1, r1, #0xff
+  orr r1, 0x100
+  orr r1, r1, 0x100
+  eor r1, 0x100
+  eor r1, r1, 0x100
+  bic r1, 0x100
+  bic r1, r1, 0x100
+
+@ CHECK: and r1, r1, #255 @ encoding: [0x01,0xf0,0xff,0x01]
+@ CHECK: and r1, r1, #255 @ encoding: [0x01,0xf0,0xff,0x01]
+@ CHECK: orr r1, r1, #256 @ encoding: [0x41,0xf4,0x80,0x71]
+@ CHECK: orr r1, r1, #256 @ encoding: [0x41,0xf4,0x80,0x71]
+@ CHECK: eor r1, r1, #256 @ encoding: [0x81,0xf4,0x80,0x71]
+@ CHECK: eor r1, r1, #256 @ encoding: [0x81,0xf4,0x80,0x71]
+@ CHECK: bic r1, r1, #256 @ encoding: [0x21,0xf4,0x80,0x71]
+@ CHECK: bic r1, r1, #256 @ encoding: [0x21,0xf4,0x80,0x71]
+
+