public void Single_basic_block_with_reassignment_of_parameter()
{
// int32 TwiceParamSquared(int32 a)
// {
// a = a * a;
// a = a + a;
// return a;
// }
const string source = @"
; #0 int32 param
BB_0:
Multiply #0 * #0 -> #0
Add #0 + #0 -> #0
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32 param
; #1 int32
; #2 int32
BB_0:
Multiply #0 * #0 -> #1
Add #1 + #1 -> #2
Return #2
";
AssertDisassembly(result, expected);
}
public void Successive_basic_blocks()
{
const string source = @"
; #0 int32 param
BB_0:
Multiply #0 * #0 -> #0
BB_1:
Add #0 + #0 -> #0
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32 param
; #1 int32
; #2 int32
BB_0:
Multiply #0 * #0 -> #1
BB_1:
Add #1 + #1 -> #2
Return #2
";
AssertDisassembly(result, expected);
}
public void Single_basic_block_with_same_variable_assigned_thrice()
{
// int32 a = 0;
// a = 1;
// a = 2;
// return a;
const string source = @"
; #0 int32
; #1 int32
; #2 int32
BB_0:
Load 0 -> #0
Load 1 -> #1
CopyValue #1 -> #0
Load 2 -> #2
CopyValue #2 -> #0
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32
; #1 int32
; #2 int32
BB_0:
Load 0 -> #0
Load 1 -> #1
Load 2 -> #2
Return #2
";
AssertDisassembly(result, expected);
}
public void Single_basic_block_with_call()
{
// int32 Caller(int32 a, bool c)
// {
// int32 b = a;
// if (c) { b = b * b; }
// return Callee(a, b, b + b);
// }
const string source = @"
; #0 int32 param
; #1 bool param
; #2 int32
; #3 int32
; #4 int32
; #5 int32
BB_0:
CopyValue #0 -> #2
BranchIf #1 ==> BB_1
==> BB_2
BB_1:
Multiply #2 * #2 -> #3
CopyValue #3 -> #2
BB_2:
Add #2 + #2 -> #4
Call Test::Callee(#0, #2, #4) -> #5
Return #5
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// Value #5 is expected to be unused (created in Phi construction)
const string expected = @"
; #0 int32 param
; #1 bool param
; #2 int32
; #3 int32
; #4 int32
; #5 int32
; #6 int32
BB_0:
BranchIf #1 ==> BB_1
==> BB_2
BB_1:
Multiply #0 * #0 -> #2
BB_2:
PHI (#0, #2) -> #3
Add #3 + #3 -> #4
Call Test::Callee(#0, #3, #4) -> #6
Return #6
";
AssertDisassembly(result, expected);
}
public int ConvertLargeAndSmallMethod()
{
// This test reuses the SsaConverter instance to exercise caching
var converter = new SsaConverter();
var large = converter.ConvertToSsa(_largeMethod);
var small = converter.ConvertToSsa(_smallMethod);
return(large.Values.Count + small.Values.Count);
}
public void Branch_that_merges_back_and_produces_phi()
{
// int32 f(int32 value, bool square)
// {
// int32 result = value;
// if (square) { result = result * result; }
// return result;
// }
const string source = @"
; #0 int32 param
; #1 bool param
; #2 int32
; #3 int32
BB_0:
CopyValue #0 -> #2
BranchIf #1 ==> BB_1
==> BB_2
BB_1:
Multiply #2 * #2 -> #3
CopyValue #3 -> #2
BB_2:
Return #2
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32 param
; #1 bool param
; #2 int32
; #3 int32
BB_0:
BranchIf #1 ==> BB_1
==> BB_2
BB_1:
Multiply #0 * #0 -> #2
BB_2:
PHI (#0, #2) -> #3
Return #3
";
AssertDisassembly(result, expected);
}
public void Trivial_phi_is_optimized_away_in_complete_cfg()
{
// int32 F(bool p, int32 v)
// {
// int32 result = v;
// if (p) { result = v; }
// return result;
// }
const string source = @"
; #0 bool param
; #1 int32 param
; #2 int32
BB_0:
CopyValue #1 -> #2
BranchIf #0 ==> BB_1
==> BB_2
BB_1:
CopyValue #1 -> #2
BB_2:
Return #2
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// PHI(#1, #1) is optimized away.
// Note that an unused value (#2) is created but it should hurt no-one, and can be removed in optimization.
const string expected = @"
; #0 bool param
; #1 int32 param
; #2 int32
BB_0:
BranchIf #0 ==> BB_1
==> BB_2
BB_1:
BB_2:
Return #1
";
AssertDisassembly(result, expected);
}
public void Void_returns_use_shared_value()
{
// void F(bool p)
// {
// if (p) { return; }
// }
const string source = @"
; #0 bool param
; #1 void
; #2 void
BB_0:
BranchIf #0 ==> BB_1
==> BB_2
BB_1:
Return #1
BB_2:
Return #2
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// The same (uninitialized) void value is used for both returns
const string expected = @"
; #0 bool param
; #1 void
BB_0:
BranchIf #0 ==> BB_1
==> BB_2
BB_1:
Return #1
BB_2:
Return #1
";
AssertDisassembly(result, expected);
}
public void Single_basic_block_with_already_ssa_arithmetic_on_parameters()
{
// int32 f(int32 a, int32 b)
// {
// int32 c = a + b;
// return c - a;
// }
const string source = @"
; #0 int32 param
; #1 int32 param
; #2 int32
; #3 int32
BB_0:
Add #0 + #1 -> #2
Subtract #2 - #0 -> #3
Return #3
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// The source is already in SSA form, so no diff is expected
AssertDisassembly(result, source);
}
public void Branch_that_does_not_merge_back()
{
const string source = @"
; #0 int32 param
; #1 bool param
; #2 int32
BB_0:
BranchIf #1 ==> BB_1
==> BB_2
BB_1:
Multiply #0 * #0 -> #2
Return #2
BB_2:
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// No change expected
AssertDisassembly(result, source);
}
public void Operands_in_non_trivial_phi_are_not_removed()
{
// int32 F(int32 a, int32 b)
// {
// int32 result = a;
// if (b % 2 == 0) { result = b; }
// else if (b % 3 == 0) { result = b; }
// return result;
// }
const string source = @"
; #0 int32 param
; #1 int32 param
; #2 int32
; #3 int32
; #4 int32
; #5 int32
; #6 bool
; #7 int32
; #8 int32
; #9 int32
; #10 bool
BB_0:
CopyValue #0 -> #2
Load 2 -> #3
Modulo #1 % #3 -> #4
Load 0 -> #5
Equal #4 == #5 -> #6
BranchIf #6 ==> BB_1
==> BB_2
BB_1:
CopyValue #1 -> #2
==> BB_4
BB_2:
Load 3 -> #7
Modulo #1 % #7 -> #8
Load 0 -> #9
Equal #8 == #9 -> #10
BranchIf #10 ==> BB_3
==> BB_4
BB_3:
CopyValue #1 -> #2
BB_4:
Return #2
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
// The duplicate operand in PHI (#0, #1, #1) is not optimized away, as it encodes information
// which value comes from which branch.
const string expected = @"
; #0 int32 param
; #1 int32 param
; #2 int32
; #3 int32
; #4 int32
; #5 bool
; #6 int32
; #7 int32
; #8 int32
; #9 bool
; #10 int32
BB_0:
Load 2 -> #2
Modulo #1 % #2 -> #3
Load 0 -> #4
Equal #3 == #4 -> #5
BranchIf #5 ==> BB_1
==> BB_2
BB_1:
==> BB_4
BB_2:
Load 3 -> #6
Modulo #1 % #6 -> #7
Load 0 -> #8
Equal #7 == #8 -> #9
BranchIf #9 ==> BB_3
==> BB_4
BB_3:
BB_4:
PHI (#0, #1, #1) -> #10
Return #10
";
AssertDisassembly(result, expected);
}
public void While_loop_where_iteration_variable_has_more_complex_phi()
{
// int32 CountToTen()
// {
// int32 result = 0;
// while (result < 10)
// {
// if (result % 2 == 0) { result = result + 1; }
// else { result = result + 2; }
// }
// return result;
// }
const string source = @"
; #0 int32
; #1 int32
; #2 bool
; #3 int32
; #4 int32
; #5 int32
; #6 bool
; #7 int32
; #8 int32
; #9 int32
; #10 int32
BB_0:
Load 0 -> #0
BB_1:
Load 10 -> #1
Less #0 < #1 -> #2
BranchIf #2 ==> BB_2
==> BB_6
BB_2:
Load 2 -> #3
Modulo #0 % #3 -> #4
Load 0 -> #5
Equal #4 == #5 -> #6
BranchIf #6 ==> BB_3
==> BB_4
BB_3:
Load 1 -> #7
Add #0 + #7 -> #8
CopyValue #8 -> #0
==> BB_5
BB_4:
Load 2 -> #9
Add #0 + #9 -> #10
CopyValue #10 -> #0
BB_5:
==> BB_1
BB_6:
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32
; #1 int32
; #2 int32
; #3 bool
; #4 int32
; #5 int32
; #6 int32
; #7 bool
; #8 int32
; #9 int32
; #10 int32
; #11 int32
; #12 int32
BB_0:
Load 0 -> #0
BB_1:
PHI (#0, #12) -> #2
Load 10 -> #1
Less #2 < #1 -> #3
BranchIf #3 ==> BB_2
==> BB_6
BB_2:
Load 2 -> #4
Modulo #2 % #4 -> #5
Load 0 -> #6
Equal #5 == #6 -> #7
BranchIf #7 ==> BB_3
==> BB_4
BB_3:
Load 1 -> #8
Add #2 + #8 -> #9
==> BB_5
BB_4:
Load 2 -> #10
Add #2 + #10 -> #11
BB_5:
PHI (#11, #9) -> #12
==> BB_1
BB_6:
Return #2
";
AssertDisassembly(result, expected);
}
public void Simple_while_loop()
{
// int32 CountToTen()
// {
// int32 result = 0;
// while (result < 10) { result = result + 1; }
// return result;
// }
const string source = @"
; #0 int32
; #1 int32
; #2 bool
; #3 int32
; #4 int32
BB_0:
Load 0 -> #0
BB_1:
Load 10 -> #1
Less #0 < #1 -> #2
BranchIf #2 ==> BB_2
==> BB_3
BB_2:
Load 1 -> #3
Add #0 + #3 -> #4
CopyValue #4 -> #0
==> BB_1
BB_3:
Return #0
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32
; #1 int32
; #2 int32
; #3 bool
; #4 int32
; #5 int32
BB_0:
Load 0 -> #0
BB_1:
PHI (#0, #5) -> #2
Load 10 -> #1
Less #2 < #1 -> #3
BranchIf #3 ==> BB_2
==> BB_3
BB_2:
Load 1 -> #4
Add #2 + #4 -> #5
==> BB_1
BB_3:
Return #2
";
AssertDisassembly(result, expected);
}
public void Branch_that_merges_back_three_way_and_produces_one_phi()
{
// int32 f(bool a, bool b)
// {
// int32 result = 0;
// if (a & b) { result = 3; }
// else if (a) { result = 2; }
// return result;
// }
const string source = @"
; #0 bool param
; #1 bool param
; #2 int32
; #3 bool
; #4 int32
; #5 int32
BB_0:
Load 0 -> #2
BitwiseAnd #0 & #1 -> #3
BranchIf #3 ==> BB_1
==> BB_2
BB_1:
Load 3 -> #4
CopyValue #4 -> #2
==> BB_4
BB_2:
BranchIf #0 ==> BB_3
==> BB_4
BB_3:
Load 2 -> #5
CopyValue #5 -> #2
BB_4:
Return #2
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 bool param
; #1 bool param
; #2 int32
; #3 bool
; #4 int32
; #5 int32
; #6 int32
BB_0:
Load 0 -> #2
BitwiseAnd #0 & #1 -> #3
BranchIf #3 ==> BB_1
==> BB_2
BB_1:
Load 3 -> #4
==> BB_4
BB_2:
BranchIf #0 ==> BB_3
==> BB_4
BB_3:
Load 2 -> #5
BB_4:
PHI (#2, #5, #4) -> #6
Return #6
";
AssertDisassembly(result, expected);
}
public void Double_branch_that_merges_back_and_produces_phis_in_two_blocks()
{
// int32 f(int32 value, bool square, bool twice)
// {
// int32 result = value;
// if (square) {
// result = result * result;
// if (twice) { result = result * result; }
// }
// return result;
// }
const string source = @"
; #0 int32 param
; #1 bool param
; #2 bool param
; #3 int32
; #4 int32
; #5 int32
BB_0:
CopyValue #0 -> #3
BranchIf #1 ==> BB_1
==> BB_4
BB_1:
Multiply #3 * #3 -> #4
CopyValue #4 -> #3
BranchIf #2 ==> BB_2
==> BB_3
BB_2:
Multiply #3 * #3 -> #5
CopyValue #5 -> #3
BB_3:
BB_4:
Return #3
";
var original = MethodAssembler.Assemble(source, "Test::Method");
var result = new SsaConverter().ConvertToSsa(original);
const string expected = @"
; #0 int32 param
; #1 bool param
; #2 bool param
; #3 int32
; #4 int32
; #5 int32
; #6 int32
BB_0:
BranchIf #1 ==> BB_1
==> BB_4
BB_1:
Multiply #0 * #0 -> #3
BranchIf #2 ==> BB_2
==> BB_3
BB_2:
Multiply #3 * #3 -> #4
BB_3:
PHI (#3, #4) -> #6
BB_4:
PHI (#0, #6) -> #5
Return #5
";
AssertDisassembly(result, expected);
}
