[arm-fast-isel] Add support for ARM PIC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162823 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 436b6ac4d090217cbcdd71ac76befb70301740d6..9849cb57d191b3db786d06e1241f83b23d06c07d 100644 (file)
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -617,10 +617,7 @@ unsigned ARMFastISel::ARMMaterializeGV(const GlobalValue *GV, EVT VT) {
   if (VT != MVT::i32) return 0;
 
   Reloc::Model RelocM = TM.getRelocationModel();
-
-  // TODO: Need more magic for ARM PIC.
-  if (!isThumb2 && (RelocM == Reloc::PIC_)) return 0;
-
+  bool IsIndirect = Subtarget->GVIsIndirectSymbol(GV, RelocM);
   unsigned DestReg = createResultReg(TLI.getRegClassFor(VT));
 
   // Use movw+movt when possible, it avoids constant pool entries.
@@ -668,17 +665,30 @@ unsigned ARMFastISel::ARMMaterializeGV(const GlobalValue *GV, EVT VT) {
         .addConstantPoolIndex(Idx);
       if (RelocM == Reloc::PIC_)
         MIB.addImm(Id);
+      AddOptionalDefs(MIB);
     } else {
       // The extra immediate is for addrmode2.
       MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(ARM::LDRcp),
                     DestReg)
         .addConstantPoolIndex(Idx)
         .addImm(0);
+      AddOptionalDefs(MIB);
+
+      if (RelocM == Reloc::PIC_) {
+        unsigned Opc = IsIndirect ? ARM::PICLDR : ARM::PICADD;
+        unsigned NewDestReg = createResultReg(TLI.getRegClassFor(VT));
+
+        MachineInstrBuilder MIB = BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
+                                          DL, TII.get(Opc), NewDestReg)
+                                  .addReg(DestReg)
+                                  .addImm(Id);
+        AddOptionalDefs(MIB);
+        return NewDestReg;
+      }
     }
-    AddOptionalDefs(MIB);
   }
 
-  if (Subtarget->GVIsIndirectSymbol(GV, RelocM)) {
+  if (IsIndirect) {
     MachineInstrBuilder MIB;
     unsigned NewDestReg = createResultReg(TLI.getRegClassFor(VT));
     if (isThumb2)

diff --git a/test/CodeGen/ARM/fast-isel-pic.ll b/test/CodeGen/ARM/fast-isel-pic.ll
new file mode 100644 (file)
index 0000000..392a845
--- /dev/null
+++ b/test/CodeGen/ARM/fast-isel-pic.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=thumbv7-apple-ios | FileCheck %s --check-prefix=THUMB
+; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=arm-apple-ios | FileCheck %s --check-prefix=ARM
+; RUN: llc < %s -O0 -fast-isel-abort -relocation-model=pic -mtriple=armv7-apple-ios | FileCheck %s --check-prefix=ARMv7
+
+@g = global i32 0, align 4
+
+define i32 @LoadGV() {
+entry:
+; THUMB: LoadGV
+; THUMB: movw [[reg0:r[0-9]+]],
+; THUMB: movt [[reg0]],
+; THUMB: add  [[reg0]], pc
+; ARM: LoadGV
+; ARM: ldr [[reg1:r[0-9]+]],
+; ARM: add [[reg1]], pc, [[reg1]]
+; ARMv7: LoadGV
+; ARMv7: movw [[reg2:r[0-9]+]],
+; ARMv7: movt [[reg2]],
+; ARMv7: add  [[reg2]], pc, [[reg2]]
+  %tmp = load i32* @g
+  ret i32 %tmp
+}
+
+@i = external global i32
+
+define i32 @LoadIndirectSymbol() {
+entry:
+; THUMB: LoadIndirectSymbol
+; THUMB: movw r[[reg3:[0-9]+]],
+; THUMB: movt r[[reg3]],
+; THUMB: add  r[[reg3]], pc
+; THUMB: ldr  r[[reg3]], [r[[reg3]]]
+; ARM: LoadIndirectSymbol
+; ARM: ldr [[reg4:r[0-9]+]],
+; ARM: ldr [[reg4]], [pc, [[reg4]]]
+; ARMv7: LoadIndirectSymbol
+; ARMv7: movw r[[reg5:[0-9]+]],
+; ARMv7: movt r[[reg5]],
+; ARMv7: add  r[[reg5]], pc, r[[reg5]]
+; ARMv7: ldr  r[[reg5]], [r[[reg5]]]
+  %tmp = load i32* @i
+  ret i32 %tmp
+}