Subzero: Be more strict about i1 calculations.

src/IceInstX8632.cpp

 //===- subzero/src/IceInstX8632.cpp - X86-32 instruction implementation ---===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the InstX8632 and OperandX8632 classes,
@@ skipping 575 matching lines @@
 
 template <> void InstX8632Pblendvb::emit(const Cfg *Func) const {
   assert(static_cast<TargetX8632 *>(Func->getTarget())->getInstructionSet() >=
          TargetX8632::SSE4_1);
   emitVariableBlendInst(Opcode, this, Func);
 }
 
 template <> void InstX8632Imul::emit(const Cfg *Func) const {
   Ostream &Str = Func->getContext()->getStrEmit();
   assert(getSrcSize() == 2);
-  if (getDest()->getType() == IceType_i8) {
+  if (getDest()->getType() == IceType_i1 ||

[jvoung (off chromium), 2014/09/05 23:07:15]

I don't think arithmetic is allowed on i1, only and/or/xor bitwise ops:

"add, sub, mul, shl, udiv, sdiv, urem, srem, lshr, ashr

These arithmetic operations are disallowed on values of type i1."

See: test/Transforms/NaCl/promote-i1-ops.ll

How are you seeing these?

[Jim Stichnoth, 2014/09/05 23:46:48]

Interesting, I didn't realize we were simplifying those away, so, awesome! :)

I was hand-constructing the i1 tests for this CL.  The problem I actually saw,
that started it all, was bitcode that did an xor of an i1 with the true
constant, and Subzero lowered it as an xor with the immediate -1 (0xff) instead
of 1, which caused problems with a subsequent 8-bit compare against 0.

I'll take another look and see what parts are really needed given the PNaCl
simplfications.

+      getDest()->getType() == IceType_i8) {
     // The 8-bit version of imul only allows the form "imul r/m8".
     Variable *Src0 = llvm::dyn_cast<Variable>(getSrc(0));
     (void)Src0;
     assert(Src0 && Src0->getRegNum() == TargetX8632::Reg_eax);
     Str << "\timul\t";
     getSrc(1)->emit(Func);
     Str << "\n";
   } else if (llvm::isa<Constant>(getSrc(1))) {
     Str << "\timul\t";
     getDest()->emit(Func);
@@ skipping 866 matching lines @@
   default:
     Str << "???";
     break;
   }
   Str << "(";
   Var->dump(Func);
   Str << ")";
 }
 
 } // end of namespace Ice