Implement bigint absAdd, absSub, mulAdd, sqrAdd, estQuotientDigit intrinsics,

runtime/vm/assembler_x64_test.cc

Index: runtime/vm/assembler_x64_test.cc
===================================================================
--- runtime/vm/assembler_x64_test.cc	(revision 41040)
+++ runtime/vm/assembler_x64_test.cc	(working copy)
@@ -386,6 +386,21 @@
 }
 
 
+ASSEMBLER_TEST_GENERATE(UnsignedMultiply, assembler) {
+  __ movl(RAX, Immediate(-1));
+  __ movl(RCX, Immediate(16));
+  __ mull(RCX);

[zra, 2014/10/10 16:23:43]

A comment about what is going on here might be good since 15 is sort of
non-intuitive as the expected result.

[regis, 2014/10/10 19:15:47]

Done.

+  __ movq(RAX, RDX);
+  __ ret();
+}
+
+
+ASSEMBLER_TEST_RUN(UnsignedMultiply, test) {
+  typedef int (*UnsignedMultiply)();
+  EXPECT_EQ(15, reinterpret_cast<UnsignedMultiply>(test->entry())());
+}
+
+
 ASSEMBLER_TEST_GENERATE(SignedMultiply64, assembler) {
   __ pushq(R15);  // Callee saved.
   __ movq(RAX, Immediate(2));
@@ -508,6 +523,21 @@
 }
 
 
+ASSEMBLER_TEST_GENERATE(UnsignedDivide, assembler) {
+  __ movl(RAX, Immediate(0x0));
+  __ movl(RDX, Immediate(0xfffffffff0000000));

[zra, 2014/10/10 16:23:43]

movq? Can you really give such a big immediate to movl? Does it set only the low
32-bits of RDX? If so why not get rid of the high bits of the immediate?

[regis, 2014/10/10 19:15:47]

If you do not specify the high bits, the value is positive instead of negative
and you get an assert fault !imm.is_int32()

I declared some locals to make it more readable.

+  __ movl(RCX, Immediate(-1));
+  __ divl(RCX);

[zra, 2014/10/10 16:23:43]

A comment here too.

[regis, 2014/10/10 19:15:47]

ditto

+  __ ret();
+}
+
+
+ASSEMBLER_TEST_RUN(UnsignedDivide, test) {
+  typedef uint32_t (*UnsignedDivide)();
+  EXPECT_EQ(0xF0000000, reinterpret_cast<UnsignedDivide>(test->entry())());
+}
+
+
 ASSEMBLER_TEST_GENERATE(SignedDivideLong, assembler) {
   __ movq(RAX, Immediate(kLargeConstant));
   __ movq(RDX, Immediate(123));
@@ -905,6 +935,17 @@
   __ movl(Address(RAX, 0), RAX);
   __ Bind(&donetest13a);
 
+  Label donetest15a;
+  __ movl(RDX, Immediate(0xffffffffff000000));

[zra, 2014/10/10 16:23:43]

Same question in the sequence with l vs. q versions of instructions with large
immediates.

[regis, 2014/10/10 19:15:47]

ditto

+  __ movl(RAX, Immediate(-1));
+  __ movl(RCX, Immediate(2));
+  __ shll(RDX, RCX);
+  __ shldl(RDX, RAX, Immediate(2));

[zra, 2014/10/10 16:23:43]

A comment here.

[regis, 2014/10/10 19:15:47]

Done.

+  __ cmpl(RDX, Immediate(0xfffffffff0000003));
+  __ j(EQUAL, &donetest15a);
+  __ int3();
+  __ Bind(&donetest15a);
+
   __ movl(RAX, Immediate(0));
   __ ret();
 }