SPIRV-Tools/test/opt/loop_optimizations/hoist_without_preheader.cpp
Steven Perron b3daa93b46 Change merge return pass to handle structured cfg.
We are seeing shaders that have multiple returns in a functions.  These
functions must get inlined for legalization purposes; however, the
inliner does not know how to inline functions that have multiple
returns.

The solution we will go with it to improve the merge return pass to
handle structured control flow.

Note that the merge return pass will assume the cfg has been cleanedup
by dead branch elimination.

Fixes #857.
2018-03-19 13:49:04 -04:00

124 lines
2.9 KiB
C++

// Copyright (c) 2018 Google LLC.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string>
#include <gmock/gmock.h>
#include "../pass_fixture.h"
#include "opt/licm_pass.h"
namespace {
using namespace spvtools;
using ::testing::UnorderedElementsAre;
using PassClassTest = PassTest<::testing::Test>;
/*
Tests that the LICM pass will generate a preheader when one is not present
Generated from the following GLSL fragment shader
--eliminate-local-multi-store has also been run on the spv binary
#version 440 core
void main(){
int a = 1;
int b = 2;
int hoist = 0;
for (int i = 0; i < 10; i++) {
if (i == 5) {
break;
}
}
for (int i = 0; i < 10; i++) {
hoist = a + b;
}
}
*/
#ifdef SPIRV_EFFCEE
TEST_F(PassClassTest, HoistWithoutPreheader) {
const std::string text = R"(OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %main "main"
OpExecutionMode %main OriginUpperLeft
OpSource GLSL 440
OpName %main "main"
%void = OpTypeVoid
%4 = OpTypeFunction %void
%int = OpTypeInt 32 1
%_ptr_Function_int = OpTypePointer Function %int
%int_1 = OpConstant %int 1
%int_2 = OpConstant %int 2
%int_0 = OpConstant %int 0
%int_10 = OpConstant %int 10
%bool = OpTypeBool
%int_5 = OpConstant %int 5
%main = OpFunction %void None %4
%13 = OpLabel
OpBranch %14
%14 = OpLabel
%15 = OpPhi %int %int_0 %13 %16 %17
; CHECK: OpLoopMerge [[preheader:%\w+]]
OpLoopMerge %25 %17 None
OpBranch %19
%19 = OpLabel
%20 = OpSLessThan %bool %15 %int_10
OpBranchConditional %20 %21 %25
%21 = OpLabel
%22 = OpIEqual %bool %15 %int_5
OpSelectionMerge %23 None
OpBranchConditional %22 %24 %23
%24 = OpLabel
OpBranch %25
%23 = OpLabel
OpBranch %17
%17 = OpLabel
%16 = OpIAdd %int %15 %int_1
OpBranch %14
; Check that we hoisted the code to the preheader
; CHECK: [[preheader]] = OpLabel
; CHECK-NEXT: OpPhi
; CHECK-NEXT: OpPhi
; CHECK-NEXT: OpIAdd
; CHECK-NEXT: OpBranch [[header:%\w+]]
; CHECK: [[header]] = OpLabel
; CHECK-NEXT: OpPhi
; CHECK-NEXT: OpPhi
; CHECK: OpLoopMerge
%25 = OpLabel
%26 = OpPhi %int %int_0 %24 %int_0 %19 %27 %28
%29 = OpPhi %int %int_0 %24 %int_0 %19 %30 %28
OpLoopMerge %31 %28 None
OpBranch %32
%32 = OpLabel
%33 = OpSLessThan %bool %29 %int_10
OpBranchConditional %33 %34 %31
%34 = OpLabel
%27 = OpIAdd %int %int_1 %int_2
OpBranch %28
%28 = OpLabel
%30 = OpIAdd %int %29 %int_1
OpBranch %25
%31 = OpLabel
OpReturn
OpFunctionEnd
)";
SinglePassRunAndMatch<opt::LICMPass>(text, false);
}
#endif
} // namespace