commit 45c5927c5cd347500d69a3ea68ee01a6a97e25b3
author Reed Kotler <rkotler@mips.com> Sun Nov 10 00:09:26 2013 +0000
committer Reed Kotler <rkotler@mips.com> Sun Nov 10 00:09:26 2013 +0000
tree d13eceb9b4a6d806eff083668129b9315ecbd479
parent 442ecd22ca5fa965bf99c7dd2bec143178893c50

Mostly finish up constant islands port for Mips for load constants.
Still need to finish the branch part. Still lots more review of the code,
clean up and testing. 

llvm-svn: 194337

llvm/lib/Target/Mips/MipsConstantIslandPass.cpp

diff --git a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
index 83ef7f7..23c988e 100644
--- a/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
+++ b/llvm/lib/Target/Mips/MipsConstantIslandPass.cpp
@@ -66,6 +66,16 @@
   cl::desc("Make small offsets be this amount for testing purposes"),
   cl::Hidden);
 
+//
+// For testing purposes we tell it to not use relaxed load forms so that it
+// will split blocks.
+//
+static cl::opt<bool> NoLoadRelaxation(
+  "mips-constant-islands-no-load-relaxation",
+  cl::init(false),
+  cl::desc("Don't relax loads to long loads - for testing purposes"),
+  cl::Hidden);
+
 
 namespace {
 
@@ -169,6 +179,9 @@
                             ConstantIslandsSmallOffset: MaxDisp;
         return xMaxDisp;
       }
+      void setMaxDisp(unsigned val) {
+        MaxDisp = val;
+      }
       unsigned getLongFormMaxDisp() const {
         return LongFormMaxDisp;
       }
@@ -615,6 +628,8 @@
             Bits = 8;
             Scale = 4;
             LongFormOpcode = Mips::LwRxPcTcpX16;
+            LongFormBits = 16;
+            LongFormScale = 1;
             break;
           case Mips::LwRxPcTcpX16:
             Bits = 16;
@@ -977,6 +992,7 @@
                        true)) {
     DEBUG(dbgs() << "In range\n");
     UserMI->setDesc(TII->get(U.getLongFormOpcode()));
+    U.setMaxDisp(U.getLongFormMaxDisp());
     return 2;  // instruction is longer length now
   }
 
@@ -1214,9 +1230,10 @@
     // No water found.
     // we first see if a longer form of the instrucion could have reached
     // the constant. in that case we won't bother to split
-#ifdef IN_PROGRESS
-    result = findLongFormInRangeCPEntry(U, UserOffset);
-#endif
+    if (!NoLoadRelaxation) {
+      result = findLongFormInRangeCPEntry(U, UserOffset);
+      if (result != 0) return true;
+    }
     DEBUG(dbgs() << "No water found\n");
     createNewWater(CPUserIndex, UserOffset, NewMBB);