[llvm-commits] [llvm] r123559 - in /llvm/trunk: lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp lib/Target/X86/X86FastISel.cpp test/CodeGen/X86/fast-isel-gep.ll

[Chris Lattner]

Author: lattner
Date: Sat Jan 15 20:27:38 2011
New Revision: 123559

URL: http://llvm.org/viewvc/llvm-project?rev=123559&view=rev
Log:
reapply my fix for PR8961 with a tweak to properly handle
multi-instruction sequences like calls.  Many thanks to Jakob for
finding a testcase.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/lib/Target/X86/X86FastISel.cpp
    llvm/trunk/test/CodeGen/X86/fast-isel-gep.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=123559&r1=123558&r2=123559&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Sat Jan 15 20:27:38 2011
@@ -771,8 +771,16 @@
   assert(RI.getOperand().isUse() &&
          "The only use of the vreg must be a use, we haven't emitted the def!");
 
+  MachineInstr *User = &*RI;
+  
+  // Set the insertion point properly.  Folding the load can cause generation of
+  // other random instructions (like sign extends) for addressing modes, make
+  // sure they get inserted in a logical place before the new instruction.
+  FuncInfo->InsertPt = User;
+  FuncInfo->MBB = User->getParent();
+
   // Ask the target to try folding the load.
-  return FastIS->TryToFoldLoad(&*RI, RI.getOperandNo(), LI);
+  return FastIS->TryToFoldLoad(User, RI.getOperandNo(), LI);
 }
 
 #ifndef NDEBUG
@@ -890,11 +898,9 @@
           if (Inst != Begin)
             BeforeInst = llvm::prior(llvm::prior(BI));
           if (BeforeInst && isa<LoadInst>(BeforeInst) &&
-              BeforeInst->hasOneUse() && *BeforeInst->use_begin() == Inst) {
-            FastIS->recomputeInsertPt();
-            if (TryToFoldFastISelLoad(cast<LoadInst>(BeforeInst), FastIS))
-              --BI; // If we succeeded, don't re-select the load.
-          }
+              BeforeInst->hasOneUse() && *BeforeInst->use_begin() == Inst &&
+              TryToFoldFastISelLoad(cast<LoadInst>(BeforeInst), FastIS))
+            --BI; // If we succeeded, don't re-select the load.
           continue;
         }
 

Modified: llvm/trunk/lib/Target/X86/X86FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FastISel.cpp?rev=123559&r1=123558&r2=123559&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FastISel.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FastISel.cpp Sat Jan 15 20:27:38 2011
@@ -1933,7 +1933,7 @@
     XII.foldMemoryOperandImpl(*FuncInfo.MF, MI, OpNo, AddrOps, Size, Alignment);
   if (Result == 0) return false;
 
-  MI->getParent()->insert(MI, Result);
+  FuncInfo.MBB->insert(FuncInfo.InsertPt, Result);
   MI->eraseFromParent();
   return true;
 }

Modified: llvm/trunk/test/CodeGen/X86/fast-isel-gep.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fast-isel-gep.ll?rev=123559&r1=123558&r2=123559&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fast-isel-gep.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fast-isel-gep.ll Sat Jan 15 20:27:38 2011
@@ -70,3 +70,20 @@
 ; X64: test4:
 ; X64: 128(%r{{.*}},%r{{.*}},8)
 }
+
+; PR8961 - Make sure the sext for the GEP addressing comes before the load that
+; is folded.
+define i64 @test5(i8* %A, i32 %I, i64 %B) nounwind {
+  %v8 = getelementptr i8* %A, i32 %I
+  %v9 = bitcast i8* %v8 to i64*
+  %v10 = load i64* %v9
+  %v11 = add i64 %B, %v10
+  ret i64 %v11
+; X64: test5:
+; X64: movslq	%esi, %rax
+; X64-NEXT: movq	(%rdi,%rax), %rax
+; X64-NEXT: addq	%rdx, %rax
+; X64-NEXT: ret
+}
+
+