- Fix a small bug while handling target constant pools (one param was missing).

- Add a smarter constant pool loading, instead of:

lui $2, %hi($CPI1_0)
addiu $2, $2, %lo($CPI1_0)
lwc1 $f0, 0($2)

Generate:

lui $2, %hi($CPI1_0)
lwc1 $f0, %lo($CPI1_0)($2)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88886 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index 42e70bb720d169e4e54c0f1b0248f39490022da9..cbcedb8ee71cc5485bcf71486b5d4caf274a9690 100644 (file)
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -170,6 +170,27 @@ SelectAddr(SDValue Op, SDValue Addr, SDValue &Offset, SDValue &Base)
         return true;
       }
     }
+
+    // When loading from constant pools, load the lower address part in
+    // the instruction itself. Instead of:
+    //  lui $2, %hi($CPI1_0)
+    //  addiu $2, $2, %lo($CPI1_0)
+    //  lwc1 $f0, 0($2)
+    // Generate:
+    //  lui $2, %hi($CPI1_0)
+    //  lwc1 $f0, %lo($CPI1_0)($2)
+    if (Addr.getOperand(0).getOpcode() == MipsISD::Hi &&
+        Addr.getOperand(1).getOpcode() == MipsISD::Lo) {
+      SDValue LoVal = Addr.getOperand(1); 
+      if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(
+          LoVal.getOperand(0))) {
+        if (!CP->getOffset()) {
+          Base = Addr.getOperand(0);
+          Offset = LoVal.getOperand(0);
+          return true;
+        }
+      }
+    }
   }
 
   Base   = Addr;

diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index acc5b030d8f5dcc3edbf7a92aa31fdb66f3d130d..c9a43b474f8ffdc8dc2f6190d580654576ba0ad0 100644 (file)
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -568,7 +568,7 @@ LowerConstantPool(SDValue Op, SelectionDAG &DAG)
   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
   Constant *C = N->getConstVal();
   SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), 
-                                         MipsII::MO_ABS_HILO);
+                                         N->getOffset(), MipsII::MO_ABS_HILO);
   // FIXME there isn't actually debug info here
   DebugLoc dl = Op.getDebugLoc();
 

diff --git a/test/CodeGen/Mips/2009-11-16-CstPoolLoad.ll b/test/CodeGen/Mips/2009-11-16-CstPoolLoad.ll
new file mode 100644 (file)
index 0000000..f59639f
--- /dev/null
+++ b/test/CodeGen/Mips/2009-11-16-CstPoolLoad.ll
@@ -0,0 +1,10 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "E-p:32:32:32-i1:8:8-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-n32"
+target triple = "mips-unknown-linux"
+
+define float @h() nounwind readnone {
+entry:
+; CHECK: lui $2, %hi($CPI1_0)
+; CHECK: lwc1 $f0, %lo($CPI1_0)($2)
+  ret float 0x400B333340000000
+}