[ARM] GlobalISel: Support G_(S|U)DIV for s32

Add support for both targets with hardware division and without. For
hardware division we have to add support throughout the pipeline
(legalizer, reg bank select, instruction select). For targets without
hardware division, we only need to mark it as a libcall.

llvm-svn: 301164

3 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstructionSelector.cpp b/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
index a99dc159d11..1c13d51a468 100644
--- a/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
+++ b/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
@@ -332,6 +332,16 @@ bool ARMInstructionSelector::select(MachineInstr &I) const {
     }
     MIB.add(predOps(ARMCC::AL)).add(condCodeOp());
     break;
+  case G_SDIV:
+    assert(TII.getSubtarget().hasDivideInARMMode() && "Unsupported operation");
+    I.setDesc(TII.get(ARM::SDIV));
+    MIB.add(predOps(ARMCC::AL));
+    break;
+  case G_UDIV:
+    assert(TII.getSubtarget().hasDivideInARMMode() && "Unsupported operation");
+    I.setDesc(TII.get(ARM::UDIV));
+    MIB.add(predOps(ARMCC::AL));
+    break;
   case G_FADD:
     if (!selectFAdd(MIB, TII, MRI))
       return false;
diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index fe9681439e6..d1c5d964d95 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -47,6 +47,13 @@ ARMLegalizerInfo::ARMLegalizerInfo(const ARMSubtarget &ST) {
     for (auto Ty : {s1, s8, s16, s32})
       setAction({Op, Ty}, Legal);
 
+  for (unsigned Op : {G_SDIV, G_UDIV}) {
+    if (ST.hasDivideInARMMode())
+      setAction({Op, s32}, Legal);
+    else
+      setAction({Op, s32}, Libcall);
+  }
+
   for (unsigned Op : {G_SEXT, G_ZEXT}) {
     setAction({Op, s32}, Legal);
     for (auto Ty : {s1, s8, s16})
diff --git a/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp b/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
index 7c5ba499550..7325817d446 100644
--- a/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMRegisterBankInfo.cpp
@@ -221,6 +221,8 @@ ARMRegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case G_ADD:
   case G_SUB:
   case G_MUL:
+  case G_SDIV:
+  case G_UDIV:
   case G_SEXT:
   case G_ZEXT:
   case G_TRUNC: