[mips] Emit two CFI offset directives per double precision SDC1/LDC1

instead of just one for FR=1 registers
Differential Revision: http://reviews.llvm.org/D4310

llvm-svn: 212769

Author: Zoran Jovanovic

llvm/lib/Target/Mips/MipsCallingConv.td

@@ -26,9 +26,9 @@ def RetCC_MipsO32 : CallingConv<[
   // f32 are returned in registers F0, F2
   CCIfType<[f32], CCAssignToReg<[F0, F2]>>,
 
-  // f64 arguments are returned in D0_64 and D1_64 in FP64bit mode or
+  // f64 arguments are returned in D0_64 and D2_64 in FP64bit mode or
   // in D0 and D1 in FP32bit mode.
-  CCIfType<[f64], CCIfSubtarget<"isFP64bit()", CCAssignToReg<[D0_64, D1_64]>>>,
+  CCIfType<[f64], CCIfSubtarget<"isFP64bit()", CCAssignToReg<[D0_64, D2_64]>>>,
   CCIfType<[f64], CCIfSubtarget<"isNotFP64bit()", CCAssignToReg<[D0, D1]>>>
 ]>;
 
@@ -247,8 +247,9 @@ def CSR_O32_FPXX : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
 def CSR_O32 : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
                                    (sequence "S%u", 7, 0))>;
 
-def CSR_O32_FP64 : CalleeSavedRegs<(add (sequence "D%u_64", 31, 20), RA, FP,
-                                        (sequence "S%u", 7, 0))>;
+def CSR_O32_FP64 :
+  CalleeSavedRegs<(add (decimate (sequence "D%u_64", 30, 20), 2), RA, FP,
+                       (sequence "S%u", 7, 0))>;
 
 def CSR_N32 : CalleeSavedRegs<(add D20_64, D22_64, D24_64, D26_64, D28_64,
                                    D30_64, RA_64, FP_64, GP_64,

llvm/lib/Target/Mips/MipsSEFrameLowering.cpp

@@ -343,6 +343,22 @@ void MipsSEFrameLowering::emitPrologue(MachineFunction &MF) const {
             MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
         BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
             .addCFIIndex(CFIIndex);
+      } else if (Mips::FGR64RegClass.contains(Reg)) {
+        unsigned Reg0 = MRI->getDwarfRegNum(Reg, true);
+        unsigned Reg1 = MRI->getDwarfRegNum(Reg, true) + 1;
+
+        if (!STI.isLittle())
+          std::swap(Reg0, Reg1);
+
+        unsigned CFIIndex = MMI.addFrameInst(
+          MCCFIInstruction::createOffset(nullptr, Reg0, Offset));
+        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+            .addCFIIndex(CFIIndex);
+
+        CFIIndex = MMI.addFrameInst(
+          MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
+        BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+            .addCFIIndex(CFIIndex);
       } else {
         // Reg is either in GPR32 or FGR32.
         unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(

llvm/test/CodeGen/Mips/cconv/return-hard-float.ll

@@ -10,6 +10,9 @@
 ; RUN: llc -mtriple=mips64-linux-gnu -relocation-model=static -mattr=-n64,+n64 < %s | FileCheck --check-prefix=ALL --check-prefix=N64 %s
 ; RUN: llc -mtriple=mips64el-linux-gnu -relocation-model=static -mattr=-n64,+n64 < %s | FileCheck --check-prefix=ALL --check-prefix=N64 %s
 
+; RUN: llc -mtriple=mips-linux-gnu -relocation-model=static -mattr=+o32,+fp64 < %s | FileCheck --check-prefix=ALL --check-prefix=032FP64 %s
+; RUN: llc -mtriple=mipsel-linux-gnu -relocation-model=static -mattr=+o32,+fp64 < %s | FileCheck --check-prefix=ALL --check-prefix=032FP64 %s
+
 ; Test the float returns for all ABI's and byte orders as specified by
 ; section 5 of MD00305 (MIPS ABIs Described).
 
@@ -44,3 +47,13 @@ entry:
 ; N32-DAG:           ldc1 $f0, %lo(double)([[R1:\$[0-9]+]])
 ; N64-DAG:           ld  [[R1:\$[0-9]+]], %got_disp(double)($1)
 ; N64-DAG:           ldc1 $f0, 0([[R1]])
+
+define { double, double } @retComplexDouble() #0 {
+  %retval = alloca { double, double }, align 8
+  %1 = load { double, double }* %retval
+  ret { double, double } %1
+}
+
+; ALL-LABEL: retComplexDouble:
+; 032FP64-DAG:      ldc1     $f0, 0($sp)
+; 032FP64-DAG:      ldc1     $f2, 8($sp)

llvm/test/CodeGen/Mips/cfi_offset.ll

@@ -0,0 +1,41 @@
+; RUN: llc -march=mips -mattr=+o32 < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EB
+; RUN: llc -march=mipsel -mattr=+o32 < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EL
+; RUN: llc -march=mips -mattr=+o32,+fpxx < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EB
+; RUN: llc -march=mipsel -mattr=+o32,+fpxx < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EL
+; RUN: llc -march=mips -mattr=+o32,+fp64 < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EB
+; RUN: llc -march=mipsel -mattr=+o32,+fp64 < %s | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EL
+
+@var = global double 0.0
+
+declare void @foo(...)
+
+define void @bar() {
+
+; CHECK-LABEL:  bar:
+
+; CHECK:  .cfi_def_cfa_offset 40
+; CHECK:  sdc1  $f22, 32($sp)
+; CHECK:  sdc1  $f20, 24($sp)
+; CHECK:  sw  $ra, 20($sp)
+; CHECK:  sw  $16, 16($sp)
+
+; CHECK-EB:  .cfi_offset 55, -8
+; CHECK-EB:  .cfi_offset 54, -4
+; CHECK-EB:  .cfi_offset 53, -16
+; CHECK-EB:  .cfi_offset 52, -12
+
+; CHECK-EL:  .cfi_offset 54, -8
+; CHECK-EL:  .cfi_offset 55, -4
+; CHECK-EL:  .cfi_offset 52, -16
+; CHECK-EL:  .cfi_offset 53, -12
+
+; CHECK:  .cfi_offset 31, -20
+; CHECK:  .cfi_offset 16, -24
+
+    %val1 = load volatile double* @var
+    %val2 = load volatile double* @var
+    call void (...)* @foo() nounwind
+    store volatile double %val1, double* @var
+    store volatile double %val2, double* @var
+    ret void
+}