[llvm] r251033 - CodeGen: increase bits allocated for LegalizeActions

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Thu Oct 22 12:20:48 2015
New Revision: 251033

URL: http://llvm.org/viewvc/llvm-project?rev=251033&view=rev
Log:
CodeGen: increase bits allocated for LegalizeActions

The array handling CondCodes only allocated 2 bits to describe the
desired action for each type. The new addition of a "LibCall" option
overflowed this and caused corruption for Custom actions.

No in-tree targets have a Custom CondCodeAction, so unfortunately it
can't be tested.

Modified:
    llvm/trunk/include/llvm/Target/TargetLowering.h

Modified: llvm/trunk/include/llvm/Target/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetLowering.h?rev=251033&r1=251032&r2=251033&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetLowering.h (original)
+++ llvm/trunk/include/llvm/Target/TargetLowering.h Thu Oct 22 12:20:48 2015
@@ -673,9 +673,9 @@ public:
            ((unsigned)VT.SimpleTy >> 4) < array_lengthof(CondCodeActions[0]) &&
            "Table isn't big enough!");
     // See setCondCodeAction for how this is encoded.
-    uint32_t Shift = 2 * (VT.SimpleTy & 0xF);
-    uint32_t Value = CondCodeActions[CC][VT.SimpleTy >> 4];
-    LegalizeAction Action = (LegalizeAction) ((Value >> Shift) & 0x3);
+    uint32_t Shift = 4 * (VT.SimpleTy & 0x7);
+    uint32_t Value = CondCodeActions[CC][VT.SimpleTy >> 3];
+    LegalizeAction Action = (LegalizeAction) ((Value >> Shift) & 0xF);
     assert(Action != Promote && "Can't promote condition code!");
     return Action;
   }
@@ -1375,12 +1375,13 @@ protected:
                          LegalizeAction Action) {
     assert(VT.isValid() && (unsigned)CC < array_lengthof(CondCodeActions) &&
            "Table isn't big enough!");
-    /// The lower 5 bits of the SimpleTy index into Nth 2bit set from the 32-bit
-    /// value and the upper 27 bits index into the second dimension of the array
+    assert((unsigned)Action < 0x10 && "too many bits for bitfield array");
+    /// The lower 3 bits of the SimpleTy index into Nth 4bit set from the 32-bit
+    /// value and the upper 29 bits index into the second dimension of the array
     /// to select what 32-bit value to use.
-    uint32_t Shift = 2 * (VT.SimpleTy & 0xF);
-    CondCodeActions[CC][VT.SimpleTy >> 4] &= ~((uint32_t)0x3 << Shift);
-    CondCodeActions[CC][VT.SimpleTy >> 4] |= (uint32_t)Action << Shift;
+    uint32_t Shift = 4 * (VT.SimpleTy & 0x7);
+    CondCodeActions[CC][VT.SimpleTy >> 3] &= ~((uint32_t)0xF << Shift);
+    CondCodeActions[CC][VT.SimpleTy >> 3] |= (uint32_t)Action << Shift;
   }
 
   /// If Opc/OrigVT is specified as being promoted, the promotion code defaults
@@ -1921,10 +1922,10 @@ private:
   /// For each condition code (ISD::CondCode) keep a LegalizeAction that
   /// indicates how instruction selection should deal with the condition code.
   ///
-  /// Because each CC action takes up 2 bits, we need to have the array size be
+  /// Because each CC action takes up 4 bits, we need to have the array size be
   /// large enough to fit all of the value types. This can be done by rounding
-  /// up the MVT::LAST_VALUETYPE value to the next multiple of 16.
-  uint32_t CondCodeActions[ISD::SETCC_INVALID][(MVT::LAST_VALUETYPE + 15) / 16];
+  /// up the MVT::LAST_VALUETYPE value to the next multiple of 8.
+  uint32_t CondCodeActions[ISD::SETCC_INVALID][(MVT::LAST_VALUETYPE + 7) / 8];
 
   ValueTypeActionImpl ValueTypeActions;