Give targets a chance to expand even standard pseudos.

Allow targets to expand COPY and other standard pseudo-instructions
before they are expanded with copyPhysReg().

This allows the target to examine the COPY instruction for extra
operands indicating it can be widened to a preferable super-register
copy.  See the ARM -widen-vmovs option.

llvm-svn: 141578

1 files changed, 12 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/ExpandPostRAPseudos.cpp b/llvm/lib/CodeGen/ExpandPostRAPseudos.cpp
index 623b67ddcd6..e2a14a8dfd9 100644
--- a/llvm/lib/CodeGen/ExpandPostRAPseudos.cpp
+++ b/llvm/lib/CodeGen/ExpandPostRAPseudos.cpp
@@ -205,6 +205,18 @@ bool ExpandPostRA::runOnMachineFunction(MachineFunction &MF) {
       MachineInstr *MI = mi;
       // Advance iterator here because MI may be erased.
       ++mi;
+
+      // Only expand pseudos.
+      if (!MI->getDesc().isPseudo())
+        continue;
+
+      // Give targets a chance to expand even standard pseudos.
+      if (TII->expandPostRAPseudo(MI)) {
+        MadeChange = true;
+        continue;
+      }
+
+      // Expand standard pseudos.
       switch (MI->getOpcode()) {
       case TargetOpcode::SUBREG_TO_REG:
         MadeChange |= LowerSubregToReg(MI);
@@ -217,10 +229,6 @@ bool ExpandPostRA::runOnMachineFunction(MachineFunction &MF) {
       case TargetOpcode::INSERT_SUBREG:
       case TargetOpcode::EXTRACT_SUBREG:
         llvm_unreachable("Sub-register pseudos should have been eliminated.");
-      default:
-        if (MI->getDesc().isPseudo())
-          MadeChange |= TII->expandPostRAPseudo(MI);
-        break;
       }
     }
   }