Fix Subzero binary instruction to allow optional flags argument.

src/PNaClTranslator.cpp

@@ -2198,8 +2198,12 @@ void FunctionParser::ProcessRecord() {
     return;
   }
   case naclbitc::FUNC_CODE_INST_BINOP: {
-    // BINOP: [opval, opval, opcode]
-    if (!isValidRecordSize(3, "binop"))
+    // Note: Old bitcode files may have an additional 'flags' operand, which is
+    // ignored.
+
+    // BINOP: [opval, opval, opcode, [flags]]
+
+    if (!isValidRecordSizeInRange(3, 4, "binop"))
       return;
     Ice::Operand *Op1 = getRelativeOperand(Values[0], BaseIndex);
     Ice::Operand *Op2 = getRelativeOperand(Values[1], BaseIndex);

tests_lit/reader_tests/Inputs/binop-newform.tbc

+65535,8,2;
+1,1;
+65535,17,2;
+1,3;
+7,32;
+21,0,0,0,0;
+2;
+65534;
+8,1,0,0,3;
+65535,19,2;
+5,0;
+65534;
+65535,12,4;
+1,1;
+2,2,1,0;
+10,1;
+65534;
+65534;

tests_lit/reader_tests/Inputs/binop-oldform.tbc

+65535,8,2;
+1,1;
+65535,17,2;
+1,3;
+7,32;
+21,0,0,0,0;
+2;
+65534;
+8,1,0,0,3;
+65535,19,2;
+5,0;
+65534;
+65535,12,4;
+1,1;
+2,2,1,0,5169;
+10,1;
+65534;
+65534;

tests_lit/reader_tests/binop-forms.test

+; Test if we recognize both the old and the new forms of a binary instruction.
+
+; REQUIRES: no_minimal_build
+
+; Checks that the new form of binary add (without flags argument) works.
+; RUN: %pnacl_sz -verbose inst,global_init -notranslate \
+; RUN:   -threads=0 -bitcode-as-text %p/Inputs/binop-newform.tbc \
+; RUN: | FileCheck %s
+
+; Checks that the old form of binary add (with flags argument) works.
+; RUN: %pnacl_sz -verbose inst,global_init -notranslate \
+; RUN:   -threads=0 -bitcode-as-text %p/Inputs/binop-oldform.tbc \
+; RUN: | FileCheck %s
+
+; CHECK: define internal i32 @Function(i32 %__0, i32 %__1) {
+; CHECK: __0:
+; CHECK:   %__2 = add i32 %__0, %__1
+; CHECK:   ret i32 %__2
+; CHECK: }