[mips] Refactor saved-registers bitmask creation in MipsAsmPrinter::printSavedRegsBitmask. NFC.

Summary:
Make the code more readable by fusing the for-loops together and explicitly checking for each register class.

Also, this version is more straightforward because it doesn't assume that FPU registers always come before CPU registers in the CalleeSavedInfo vector.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8033

llvm-svn: 234475

1 files changed, 11 insertions, 20 deletions

diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
index 1eb3b2c6568..9024f21c00e 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -260,31 +260,22 @@ void MipsAsmPrinter::printSavedRegsBitmask() {
   unsigned AFGR64RegSize = Mips::AFGR64RegClass.getSize();
   bool HasAFGR64Reg = false;
   unsigned CSFPRegsSize = 0;
-  unsigned i, e = CSI.size();
-
-  // Set FPU Bitmask.
-  for (i = 0; i != e; ++i) {
-    unsigned Reg = CSI[i].getReg();
-    if (Mips::GPR32RegClass.contains(Reg))
-      break;
 
+  for (const auto &I : CSI) {
+    unsigned Reg = I.getReg();
     unsigned RegNum = TRI->getEncodingValue(Reg);
-    if (Mips::AFGR64RegClass.contains(Reg)) {
+
+    // If it's a floating point register, set the FPU Bitmask.
+    // If it's a general purpose register, set the CPU Bitmask.
+    if (Mips::FGR32RegClass.contains(Reg)) {
+      FPUBitmask |= (1 << RegNum);
+      CSFPRegsSize += FGR32RegSize;
+    } else if (Mips::AFGR64RegClass.contains(Reg)) {
       FPUBitmask |= (3 << RegNum);
       CSFPRegsSize += AFGR64RegSize;
       HasAFGR64Reg = true;
-      continue;
-    }
-
-    FPUBitmask |= (1 << RegNum);
-    CSFPRegsSize += FGR32RegSize;
-  }
-
-  // Set CPU Bitmask.
-  for (; i != e; ++i) {
-    unsigned Reg = CSI[i].getReg();
-    unsigned RegNum = TRI->getEncodingValue(Reg);
-    CPUBitmask |= (1 << RegNum);
+    } else if (Mips::GPR32RegClass.contains(Reg))
+      CPUBitmask |= (1 << RegNum);
   }
 
   // FP Regs are saved right below where the virtual frame pointer points to.