[llvm-commits] CVS: llvm/lib/Target/X86/X86ISelSimple.cpp

[Chris Lattner]

Changes in directory llvm/lib/Target/X86:

X86ISelSimple.cpp updated: 1.304 -> 1.305
---
Log message:

Codegen -1 and -0.0 more efficiently.  This implements CodeGen/X86/negatize_zero.ll


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Diffs of the changes:  (+9 -2)

Index: llvm/lib/Target/X86/X86ISelSimple.cpp
diff -u llvm/lib/Target/X86/X86ISelSimple.cpp:1.304 llvm/lib/Target/X86/X86ISelSimple.cpp:1.305
--- llvm/lib/Target/X86/X86ISelSimple.cpp:1.304	Wed Jan  5 10:30:14 2005
+++ llvm/lib/Target/X86/X86ISelSimple.cpp	Thu Jan  6 15:19:16 2005
@@ -560,8 +560,15 @@
       BuildMI(*MBB, IP, X86::FLD0, 0, R);
     else if (CFP->isExactlyValue(+1.0))
       BuildMI(*MBB, IP, X86::FLD1, 0, R);
-    else {  // FIXME: PI, other native values
-      // FIXME: Could handle -1.0 with FLD1/FCHS
+    else if (CFP->isExactlyValue(-0.0)) {
+      unsigned Tmp = makeAnotherReg(Type::DoubleTy);
+      BuildMI(*MBB, IP, X86::FLD0, 0, Tmp);
+      BuildMI(*MBB, IP, X86::FCHS, 1, R).addReg(Tmp);      
+    } else if (CFP->isExactlyValue(-1.0)) {
+      unsigned Tmp = makeAnotherReg(Type::DoubleTy);
+      BuildMI(*MBB, IP, X86::FLD1, 0, Tmp);
+      BuildMI(*MBB, IP, X86::FCHS, 1, R).addReg(Tmp);      
+    } else {  // FIXME: PI, other native values
       // FIXME: 2*PI -> LDPI + FADD
 
       // Otherwise we need to spill the constant to memory.