From 8b6a9c157453b220a9988d3d78653f0fe36e9e55 Mon Sep 17 00:00:00 2001
From: Jim Grosbach <grosbach@apple.com>
Date: Thu, 14 Oct 2010 22:57:13 +0000
Subject: [PATCH] Refactor the MOVsr[al]_flag and RRX pseudo-instructions to
 really be pseudos and let the ARMExpandPseudoInsts pass fix them up into the
 real (MOVs) instruction form.

llvm-svn: 116534
---
 llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp | 29 ++++++++++++++++++++
 llvm/lib/Target/ARM/ARMInstrInfo.td          | 18 ++++++------
 llvm/test/CodeGen/ARM/long_shift.ll          |  2 +-
 3 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp b/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
index 6755487b4413..5dceeb1967f8 100644
--- a/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
@@ -16,6 +16,7 @@
 
 #define DEBUG_TYPE "arm-pseudo"
 #include "ARM.h"
+#include "ARMAddressingModes.h"
 #include "ARMBaseInstrInfo.h"
 #include "ARMRegisterInfo.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
@@ -575,6 +576,34 @@ bool ARMExpandPseudo::ExpandMBB(MachineBasicBlock &MBB) {
       ModifiedOp = false;
       break;
 
+    case ARM::MOVsrl_flag:
+    case ARM::MOVsra_flag: {
+      // These are just fancy MOVs insructions.
+      MachineInstrBuilder MIB =
+        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(ARM::MOVs),
+                               MI.getOperand(0).getReg())
+        .addOperand(MI.getOperand(1))
+        .addReg(0)
+        .addImm(ARM_AM::getSORegOpc((Opcode == ARM::MOVsrl_flag ? ARM_AM::lsr
+                                     : ARM_AM::asr), 1)))
+        .addReg(ARM::CPSR);
+      TransferImpOps(MI, MIB, MIB);
+      MI.eraseFromParent();
+      break;
+    }
+    case ARM::RRX: {
+      // This encodes as "MOVs Rd, Rm, rrx
+      MachineInstrBuilder MIB =
+        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(ARM::MOVs),
+                               MI.getOperand(0).getReg())
+        .addOperand(MI.getOperand(1))
+        .addOperand(MI.getOperand(1))
+        .addImm(ARM_AM::getSORegOpc(ARM_AM::rrx, 0)))
+        .addReg(0);
+      TransferImpOps(MI, MIB, MIB);
+      MI.eraseFromParent();
+      break;
+    }
     case ARM::tLDRpci_pic:
     case ARM::t2LDRpci_pic: {
       unsigned NewLdOpc = (Opcode == ARM::tLDRpci_pic)
diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index 5a2070d8c89e..1b6d3e0f8069 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -1686,20 +1686,20 @@ def : ARMPat<(or GPR:$src, 0xffff0000), (MOVTi16 GPR:$src, 0xffff)>,
       Requires<[IsARM, HasV6T2]>;
 
 let Uses = [CPSR] in
-def RRX: AsI1<0b1101, (outs GPR:$Rd), (ins GPR:$Rm), Pseudo, IIC_iMOVsi,
-              "rrx", "\t$Rd, $Rm",
-              [(set GPR:$Rd, (ARMrrx GPR:$Rm))]>, UnaryDP;
+def RRX: PseudoInst<(outs GPR:$Rd), (ins GPR:$Rm), IIC_iMOVsi, "",
+                    [(set GPR:$Rd, (ARMrrx GPR:$Rm))]>, UnaryDP,
+                    Requires<[IsARM]>;
 
 // These aren't really mov instructions, but we have to define them this way
 // due to flag operands.
 
 let Defs = [CPSR] in {
-def MOVsrl_flag : AI1<0b1101, (outs GPR:$dst), (ins GPR:$src), Pseudo,
-                      IIC_iMOVsi, "movs", "\t$dst, $src, lsr #1",
-                      [(set GPR:$dst, (ARMsrl_flag GPR:$src))]>, UnaryDP;
-def MOVsra_flag : AI1<0b1101, (outs GPR:$dst), (ins GPR:$src), Pseudo,
-                      IIC_iMOVsi, "movs", "\t$dst, $src, asr #1",
-                      [(set GPR:$dst, (ARMsra_flag GPR:$src))]>, UnaryDP;
+def MOVsrl_flag : PseudoInst<(outs GPR:$dst), (ins GPR:$src), IIC_iMOVsi, "",
+                      [(set GPR:$dst, (ARMsrl_flag GPR:$src))]>, UnaryDP,
+                      Requires<[IsARM]>;
+def MOVsra_flag : PseudoInst<(outs GPR:$dst), (ins GPR:$src), IIC_iMOVsi, "",
+                      [(set GPR:$dst, (ARMsra_flag GPR:$src))]>, UnaryDP,
+                      Requires<[IsARM]>;
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/ARM/long_shift.ll b/llvm/test/CodeGen/ARM/long_shift.ll
index 4d2243a2aa33..5e4f5730f8d2 100644
--- a/llvm/test/CodeGen/ARM/long_shift.ll
+++ b/llvm/test/CodeGen/ARM/long_shift.ll
@@ -2,7 +2,7 @@
 
 define i64 @f0(i64 %A, i64 %B) {
 ; CHECK: f0
-; CHECK:      movs    r3, r3, lsr #1
+; CHECK:      lsrs    r3, r3, #1
 ; CHECK-NEXT: rrx     r2, r2
 ; CHECK-NEXT: subs    r0, r0, r2
 ; CHECK-NEXT: sbc     r1, r1, r3