[llvm-commits] [llvm] r107393 - in /llvm/trunk: lib/CodeGen/LLVMTargetMachine.cpp lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp test/CodeGen/X86/fast-isel-loads.ll

[Dan Gohman]

Author: djg
Date: Thu Jul  1 07:15:30 2010
New Revision: 107393

URL: http://llvm.org/viewvc/llvm-project?rev=107393&view=rev
Log:
Temporarily disable on-demand fast-isel.

Modified:
    llvm/trunk/lib/CodeGen/LLVMTargetMachine.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/test/CodeGen/X86/fast-isel-loads.ll

Modified: llvm/trunk/lib/CodeGen/LLVMTargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LLVMTargetMachine.cpp?rev=107393&r1=107392&r2=107393&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LLVMTargetMachine.cpp (original)
+++ llvm/trunk/lib/CodeGen/LLVMTargetMachine.cpp Thu Jul  1 07:15:30 2010
@@ -329,15 +329,19 @@
   if (OptLevel != CodeGenOpt::None)
     PM.add(createOptimizePHIsPass());
 
-  if (OptLevel != CodeGenOpt::None) {
-    // With optimization, dead code should already be eliminated. However
-    // there is one known exception: lowered code for arguments that are only
-    // used by tail calls, where the tail calls reuse the incoming stack
-    // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
-    PM.add(createDeadMachineInstructionElimPass());
-    printAndVerify(PM, "After codegen DCE pass",
-                   /* allowDoubleDefs= */ true);
+  // Delete dead machine instructions regardless of optimization level.
+  //
+  // At -O0, fast-isel frequently creates dead instructions.
+  //
+  // With optimization, dead code should already be eliminated. However
+  // there is one known exception: lowered code for arguments that are only
+  // used by tail calls, where the tail calls reuse the incoming stack
+  // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll).
+  PM.add(createDeadMachineInstructionElimPass());
+  printAndVerify(PM, "After codegen DCE pass",
+                 /* allowDoubleDefs= */ true);
 
+  if (OptLevel != CodeGenOpt::None) {
     PM.add(createOptimizeExtsPass());
     if (!DisableMachineLICM)
       PM.add(createMachineLICMPass());

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=107393&r1=107392&r2=107393&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Thu Jul  1 07:15:30 2010
@@ -709,11 +709,13 @@
       FastIS->startNewBlock(BB);
       // Do FastISel on as many instructions as possible.
       for (; BI != End; ++BI) {
+#if 0
         // Defer instructions with no side effects; they'll be emitted
         // on-demand later.
         if (BI->isSafeToSpeculativelyExecute() &&
             !FuncInfo->isExportedInst(BI))
           continue;
+#endif
 
         // Try to select the instruction with FastISel.
         if (FastIS->SelectInstruction(BI))

Modified: llvm/trunk/test/CodeGen/X86/fast-isel-loads.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fast-isel-loads.ll?rev=107393&r1=107392&r2=107393&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fast-isel-loads.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fast-isel-loads.ll Thu Jul  1 07:15:30 2010
@@ -5,7 +5,7 @@
 ; CHECK: foo:
 ; CHECK-NEXT: movq  %rdi, -8(%rsp)
 ; CHECK-NEXT: movq  %rsi, -16(%rsp)
-; CHECK-NEXT: movsd 128(%rsi,%rdi,8), %xmm0
+; CHECK: movsd 128(%rsi,%rdi,8), %xmm0
 ; CHECK-NEXT: ret
 
 define double @foo(i64 %x, double* %p) nounwind {