[llvm-commits] [llvm] r84813 - in /llvm/trunk: lib/Target/ARM/ARMISelDAGToDAG.cpp test/CodeGen/ARM/sbfx.ll

[Evan Cheng]

Author: evancheng
Date: Wed Oct 21 19:40:00 2009
New Revision: 84813

URL: http://llvm.org/viewvc/llvm-project?rev=84813&view=rev
Log:
Don't generate sbfx / ubfx with negative lsb field. Patch by David Conrad.

Modified:
    llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp
    llvm/trunk/test/CodeGen/ARM/sbfx.ll

Modified: llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp?rev=84813&r1=84812&r2=84813&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMISelDAGToDAG.cpp Wed Oct 21 19:40:00 2009
@@ -1287,7 +1287,7 @@
       assert(Srl_imm > 0 && Srl_imm < 32 && "bad amount in shift node!");
       unsigned Width = 32 - Srl_imm;
       int LSB = Srl_imm - Shl_imm;
-      if ((LSB + Width) > 32)
+      if (LSB < 0)
         return NULL;
       SDValue Reg0 = CurDAG->getRegister(0, MVT::i32);
       SDValue Ops[] = { Op.getOperand(0).getOperand(0),

Modified: llvm/trunk/test/CodeGen/ARM/sbfx.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/sbfx.ll?rev=84813&r1=84812&r2=84813&view=diff

==============================================================================
--- llvm/trunk/test/CodeGen/ARM/sbfx.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/sbfx.ll Wed Oct 21 19:40:00 2009
@@ -35,3 +35,13 @@
     %tmp2 = lshr i32 %tmp, 29
     ret i32 %tmp2
 }
+
+define i32 @f5(i32 %a) {
+entry:
+; CHECK: f5:
+; CHECK-NOT: sbfx
+; CHECK: bx
+    %tmp = shl i32 %a, 3
+    %tmp2 = ashr i32 %tmp, 1
+    ret i32 %tmp2
+}