From 3aac788365086260b4f8318c5563db54cd2d97fb Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 1 Sep 2008 08:25:56 +0000
Subject: [PATCH] Control flow instruction encodings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55601 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMInstrFormats.td | 78 ++++++++++++++++++++++++++-----
 lib/Target/ARM/ARMInstrInfo.td    | 10 ++--
 2 files changed, 71 insertions(+), 17 deletions(-)

diff --git a/lib/Target/ARM/ARMInstrFormats.td b/lib/Target/ARM/ARMInstrFormats.td
index 16fb40505e8..d60ba5f6070 100644
--- a/lib/Target/ARM/ARMInstrFormats.td
+++ b/lib/Target/ARM/ARMInstrFormats.td
@@ -135,10 +135,76 @@ class AXI<bits<4> opcod, dag oops, dag iops, Format f, string asm,
           list<dag> pattern>
   : XI<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, asm,
        "", pattern>;
+
+// Ctrl flow instructions
+class ABLpredI<bits<4> opcod, dag oops, dag iops, Format f, string opc,
+         string asm, list<dag> pattern>
+  : I<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, opc,
+      asm,"",pattern> {
+  let Inst{24}    = 1; // L bit
+  let Inst{25-27} = 5;
+}
+class ABLI<bits<4> opcod, dag oops, dag iops, Format f, string asm,
+          list<dag> pattern>
+  : XI<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, asm,
+       "", pattern> {
+  let Inst{24}    = 1; // L bit
+  let Inst{25-27} = 5;
+}
+class ABLXI<bits<4> opcod, dag oops, dag iops, Format f, string asm,
+          list<dag> pattern>
+  : XI<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, asm,
+       "", pattern> {
+  let Inst{4-7}   = 3;
+  let Inst{20-27} = 0x12;
+}
+// FIXME: BX
 class AXIx2<bits<4> opcod, dag oops, dag iops, Format f, string asm,
             list<dag> pattern>
   : XI<opcod, oops, iops, AddrModeNone, Size8Bytes, IndexModeNone, f, asm,
        "", pattern>;
+class ABI<bits<4> opcod, dag oops, dag iops, Format f, string asm,
+          list<dag> pattern>
+  : XI<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, asm,
+       "", pattern> {
+  let Inst{24}    = 0; // L bit
+  let Inst{25-27} = 5;
+}
+class ABccI<bits<4> opcod, dag oops, dag iops, Format f, string opc,
+         string asm, list<dag> pattern>
+  : I<opcod, oops, iops, AddrModeNone, Size4Bytes, IndexModeNone, f, opc,
+      asm,"",pattern> {
+  let Inst{24}    = 0; // L bit
+  let Inst{25-27} = 5;
+}
+
+// BR_JT instructions
+// == mov pc
+class JTI<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
+  : XI<opcod, oops, iops, AddrModeNone, SizeSpecial, IndexModeNone, BranchMisc,
+       asm, "", pattern> {
+  let Inst{20}    = 0; // S Bit
+  let Inst{21-24} = 0xd;
+  let Inst{26-27} = 0;
+}
+// == ldr pc
+class JTI1<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
+  : XI<opcod, oops, iops, AddrMode1, SizeSpecial, IndexModeNone, BranchMisc,
+       asm, "", pattern> {
+  let Inst{20}    = 1; // L bit
+  let Inst{21}    = 0; // W bit
+  let Inst{22}    = 0; // B bit
+  let Inst{24}    = 1; // P bit
+}
+// == add pc
+class JTI2<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
+  : XI<opcod, oops, iops, AddrMode2, SizeSpecial, IndexModeNone, BranchMisc,
+       asm, "", pattern> {
+  let Inst{20}    = 0; // S bit
+  let Inst{21-24} = 4;
+  let Inst{26-27} = 0;
+}
+
 
 // addrmode1 instructions
 class AI1<bits<4> opcod, dag oops, dag iops, Format f, string opc,
@@ -606,18 +672,6 @@ class AXI4st<bits<4> opcod, dag oops, dag iops, Format f, string asm,
 }
 
 
-// BR_JT instructions
-class JTI<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
-  : XI<opcod, oops, iops, AddrModeNone, SizeSpecial, IndexModeNone, BranchMisc,
-       asm, "", pattern>;
-class JTI1<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
-  : XI<opcod, oops, iops, AddrMode1, SizeSpecial, IndexModeNone, BranchMisc,
-       asm, "", pattern>;
-class JTI2<bits<4> opcod, dag oops, dag iops, string asm, list<dag> pattern>
-  : XI<opcod, oops, iops, AddrMode2, SizeSpecial, IndexModeNone, BranchMisc,
-       asm, "", pattern>;
-
-
 //===----------------------------------------------------------------------===//
 
 // ARMPat - Same as Pat<>, but requires that the compiler be in ARM mode.
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index cfc0625b625..b4a9f42f0d6 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -531,16 +531,16 @@ let isReturn = 1, isTerminator = 1 in
 let isCall = 1,
   Defs = [R0, R1, R2, R3, R12, LR,
           D0, D1, D2, D3, D4, D5, D6, D7, CPSR] in {
-  def BL  : AXI<0xB, (outs), (ins i32imm:$func, variable_ops), Branch,
+  def BL  : ABLI<0xB, (outs), (ins i32imm:$func, variable_ops), Branch,
                 "bl ${func:call}",
                 [(ARMcall tglobaladdr:$func)]>;
 
-  def BL_pred : AI<0xB, (outs), (ins i32imm:$func, variable_ops),
-                   Branch, "bl", " ${func:call}",
+  def BL_pred : ABLpredI<0xB, (outs), (ins i32imm:$func, variable_ops), Branch,
+                   "bl", " ${func:call}",
                    [(ARMcall_pred tglobaladdr:$func)]>;
 
   // ARMv5T and above
-  def BLX : AXI<0x2, (outs), (ins GPR:$func, variable_ops), BranchMisc,
+  def BLX : ABLXI<0x2, (outs), (ins GPR:$func, variable_ops), BranchMisc,
                 "blx $func",
                 [(ARMcall GPR:$func)]>, Requires<[IsARM, HasV5T]>;
   let Uses = [LR] in {
@@ -576,7 +576,7 @@ let isBranch = 1, isTerminator = 1 in {
 
   // FIXME: should be able to write a pattern for ARMBrcond, but can't use
   // a two-value operand where a dag node expects two operands. :( 
-  def Bcc : AI<0xA, (outs), (ins brtarget:$target), Branch,
+  def Bcc : ABccI<0xA, (outs), (ins brtarget:$target), Branch,
                "b", " $target",
                [/*(ARMbrcond bb:$target, imm:$cc, CCR:$ccr)*/]>;
 }
-- 
2.34.1