[SystemZ] Fold more spills

Add a mapping from register-based <INSN>R instructions to the corresponding
memory-based <INSN>.  Use it to cut down on the number of spill loads.

Some instructions extend their operands from smaller fields, so this
required a new TSFlags field to say how big the unextended operand is.

This optimisation doesn't trigger for C(G)R and CL(G)R because in practice
we always combine those instructions with a branch.  Adding a test for every
other case probably seems excessive, but it did catch a missed optimisation
for DSGF (fixed in r185435).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185529 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/Target/SystemZ/SystemZInstrInfo.h b/lib/Target/SystemZ/SystemZInstrInfo.h
index 8d9a3eaacf..11d486cafb 100644
--- a/lib/Target/SystemZ/SystemZInstrInfo.h
+++ b/lib/Target/SystemZ/SystemZInstrInfo.h
@@ -32,8 +32,14 @@ namespace SystemZII {
     SimpleBDXStore = (1 << 1),
     Has20BitOffset = (1 << 2),
     HasIndex       = (1 << 3),
-    Is128Bit       = (1 << 4)
+    Is128Bit       = (1 << 4),
+    AccessSizeMask = (31 << 5),
+    AccessSizeShift = 5
   };
+  static inline unsigned getAccessSize(unsigned int Flags) {
+    return (Flags & AccessSizeMask) >> AccessSizeShift;
+  }
+
   // SystemZ MachineOperand target flags.
   enum {
     // Masks out the bits for the access model.