diff --git a/src/video_core/shader/shader_jit_x64.cpp b/src/video_core/shader/shader_jit_x64.cpp
index d74b58d84bd491cce3564ce37c205403c5066ddc..c798992eccfbd537f57618531ae018dfb9d2551a 100644
--- a/src/video_core/shader/shader_jit_x64.cpp
+++ b/src/video_core/shader/shader_jit_x64.cpp
@@ -137,6 +137,15 @@ static const u8 NO_SRC_REG_SWIZZLE = 0x1b;
/// Raw constant for the destination register enable mask that indicates all components are enabled
static const u8 NO_DEST_REG_MASK = 0xf;
+/**
+ * Get the vertex shader instruction for a given offset in the current shader program
+ * @param offset Offset in the current shader program of the instruction
+ * @return Instruction at the specified offset
+ */
+static Instruction GetVertexShaderInstruction(size_t offset) {
+ return { g_state.vs.program_code[offset] };
+}
+
/**
* Loads and swizzles a source register into the specified XMM register.
* @param instr VS instruction, used for determining how to load the source register
@@ -564,10 +573,23 @@ void JitCompiler::Compile_END(Instruction instr) {
}
void JitCompiler::Compile_CALL(Instruction instr) {
- unsigned offset = instr.flow_control.dest_offset;
- while (offset < (instr.flow_control.dest_offset + instr.flow_control.num_instructions)) {
- Compile_NextInstr(&offset);
- }
+ // Need to advance the return address past the proceeding instructions, this is the number of bytes to skip
+ constexpr unsigned SKIP = 21;
+ const uintptr_t start = reinterpret_cast<uintptr_t>(GetCodePtr());
+
+ // Push return address - not using CALL because we also want to push the offset of the return before jumping
+ MOV(64, R(RAX), ImmPtr(GetCodePtr() + SKIP));
+ PUSH(RAX);
+
+ // Push offset of the return
+ PUSH(32, Imm32(instr.flow_control.dest_offset + instr.flow_control.num_instructions));
+
+ // Jump
+ FixupBranch b = J(true);
+ fixup_branches.push_back({ b, instr.flow_control.dest_offset });
+
+ // Make sure that if the above code changes, SKIP gets updated
+ ASSERT(reinterpret_cast<uintptr_t>(GetCodePtr()) - start == SKIP);
}
void JitCompiler::Compile_CALLC(Instruction instr) {
@@ -645,8 +667,8 @@ void JitCompiler::Compile_MAD(Instruction instr) {
}
void JitCompiler::Compile_IF(Instruction instr) {
- ASSERT_MSG(instr.flow_control.dest_offset > *offset_ptr, "Backwards if-statements (%d -> %d) not supported",
- *offset_ptr, instr.flow_control.dest_offset.Value());
+ ASSERT_MSG(instr.flow_control.dest_offset > last_program_counter, "Backwards if-statements (%d -> %d) not supported",
+ last_program_counter, instr.flow_control.dest_offset.Value());
// Evaluate the "IF" condition
if (instr.opcode.Value() == OpCode::Id::IFU) {
@@ -677,8 +699,8 @@ void JitCompiler::Compile_IF(Instruction instr) {
}
void JitCompiler::Compile_LOOP(Instruction instr) {
- ASSERT_MSG(instr.flow_control.dest_offset > *offset_ptr, "Backwards loops (%d -> %d) not supported",
- *offset_ptr, instr.flow_control.dest_offset.Value());
+ ASSERT_MSG(instr.flow_control.dest_offset > last_program_counter, "Backwards loops (%d -> %d) not supported",
+ last_program_counter, instr.flow_control.dest_offset.Value());
ASSERT_MSG(!looping, "Nested loops not supported");
looping = true;
@@ -706,9 +728,6 @@ void JitCompiler::Compile_LOOP(Instruction instr) {
}
void JitCompiler::Compile_JMP(Instruction instr) {
- ASSERT_MSG(instr.flow_control.dest_offset > *offset_ptr, "Backwards jumps (%d -> %d) not supported",
- *offset_ptr, instr.flow_control.dest_offset.Value());
-
if (instr.opcode.Value() == OpCode::Id::JMPC)
Compile_EvaluateCondition(instr);
else if (instr.opcode.Value() == OpCode::Id::JMPU)
@@ -718,31 +737,42 @@ void JitCompiler::Compile_JMP(Instruction instr) {
bool inverted_condition = (instr.opcode.Value() == OpCode::Id::JMPU) &&
(instr.flow_control.num_instructions & 1);
- FixupBranch b = J_CC(inverted_condition ? CC_Z : CC_NZ, true);
-
- Compile_Block(instr.flow_control.dest_offset);
- SetJumpTarget(b);
+ FixupBranch b = J_CC(inverted_condition ? CC_Z : CC_NZ, true);
+ fixup_branches.push_back({ b, instr.flow_control.dest_offset });
}
void JitCompiler::Compile_Block(unsigned end) {
- // Save current offset pointer
- unsigned* prev_offset_ptr = offset_ptr;
- unsigned offset = *prev_offset_ptr;
+ while (program_counter < end) {
+ Compile_NextInstr();
+ }
+}
- while (offset < end)
- Compile_NextInstr(&offset);
+void JitCompiler::Compile_Return() {
+ // Peek return offset on the stack and check if we're at that offset
+ MOV(64, R(RAX), MDisp(RSP, 0));
+ CMP(32, R(RAX), Imm32(program_counter));
- // Restore current offset pointer
- offset_ptr = prev_offset_ptr;
- *offset_ptr = offset;
+ // If so, jump back to before CALL
+ FixupBranch b = J_CC(CC_NZ, true);
+ ADD(64, R(RSP), Imm32(8)); // Ignore return offset that's on the stack
+ POP(RAX); // Pop off return address
+ JMPptr(R(RAX));
+ SetJumpTarget(b);
}
-void JitCompiler::Compile_NextInstr(unsigned* offset) {
- offset_ptr = offset;
+void JitCompiler::Compile_NextInstr() {
+ last_program_counter = program_counter;
+
+ auto search = return_offsets.find(program_counter);
+ if (search != return_offsets.end()) {
+ Compile_Return();
+ }
+
+ ASSERT_MSG(code_ptr[program_counter] == nullptr, "Tried to compile already compiled shader location!");
+ code_ptr[program_counter] = GetCodePtr();
- Instruction instr;
- std::memcpy(&instr, &g_state.vs.program_code[(*offset_ptr)++], sizeof(Instruction));
+ Instruction instr = GetVertexShaderInstruction(program_counter++);
OpCode::Id opcode = instr.opcode.Value();
auto instr_func = instr_table[static_cast<unsigned>(opcode)];
@@ -757,9 +787,24 @@ void JitCompiler::Compile_NextInstr(unsigned* offset) {
}
}
+void JitCompiler::FindReturnOffsets() {
+ return_offsets.clear();
+
+ for (size_t offset = 0; offset < g_state.vs.program_code.size(); ++offset) {
+ Instruction instr = GetVertexShaderInstruction(offset);
+
+ switch (instr.opcode.Value()) {
+ case OpCode::Id::CALL:
+ case OpCode::Id::CALLC:
+ case OpCode::Id::CALLU:
+ return_offsets.insert(instr.flow_control.dest_offset + instr.flow_control.num_instructions);
+ break;
+ }
+ }
+}
+
CompiledShader* JitCompiler::Compile() {
const u8* start = GetCodePtr();
- unsigned offset = g_state.regs.vs.main_offset;
// The stack pointer is 8 modulo 16 at the entry of a procedure
ABI_PushRegistersAndAdjustStack(ABI_ALL_CALLEE_SAVED, 8);
@@ -782,10 +827,27 @@ CompiledShader* JitCompiler::Compile() {
MOV(PTRBITS, R(RAX), ImmPtr(&neg));
MOVAPS(NEGBIT, MatR(RAX));
+ // Find all `CALL` instructions and identify return locations
+ FindReturnOffsets();
+
+ // Reset flow control state
+ last_program_counter = 0;
+ program_counter = 0;
looping = false;
+ code_ptr.fill(nullptr);
+ fixup_branches.clear();
+
+ // Jump to start of the shader program
+ if (g_state.regs.vs.main_offset != 0) {
+ fixup_branches.push_back({ J(true), g_state.regs.vs.main_offset });
+ }
+
+ // Compile entire program
+ Compile_Block(static_cast<unsigned>(g_state.vs.program_code.size()));
- while (offset < g_state.vs.program_code.size()) {
- Compile_NextInstr(&offset);
+ // Set the target for any incomplete branches now that the entire shader program has been emitted
+ for (const auto& branch : fixup_branches) {
+ SetJumpTarget(branch.first, code_ptr[branch.second]);
}
return (CompiledShader*)start;
diff --git a/src/video_core/shader/shader_jit_x64.h b/src/video_core/shader/shader_jit_x64.h
index 5357c964bfc460f2fe1db89f8ce2fb8715b6fa14..d6f03892da3ba26100ffb6639aa19a1ba6553692 100644
--- a/src/video_core/shader/shader_jit_x64.h
+++ b/src/video_core/shader/shader_jit_x64.h
@@ -4,6 +4,9 @@
#pragma once
+#include <set>
+#include <utility>
+
#include <nihstro/shader_bytecode.h>
#include "common/x64/emitter.h"
@@ -66,8 +69,9 @@ public:
void Compile_MAD(Instruction instr);
private:
+
void Compile_Block(unsigned end);
- void Compile_NextInstr(unsigned* offset);
+ void Compile_NextInstr();
void Compile_SwizzleSrc(Instruction instr, unsigned src_num, SourceRegister src_reg, Gen::X64Reg dest);
void Compile_DestEnable(Instruction instr, Gen::X64Reg dest);
@@ -81,13 +85,31 @@ private:
void Compile_EvaluateCondition(Instruction instr);
void Compile_UniformCondition(Instruction instr);
+ /**
+ * Emits the code to conditionally return from a subroutine envoked by the `CALL` instruction.
+ */
+ void Compile_Return();
+
BitSet32 PersistentCallerSavedRegs();
- /// Pointer to the variable that stores the current Pica code offset. Used to handle nested code blocks.
- unsigned* offset_ptr = nullptr;
+ /**
+ * Analyzes the entire shader program for `CALL` instructions before emitting any code,
+ * identifying the locations where a return needs to be inserted.
+ */
+ void FindReturnOffsets();
+
+ /// Mapping of Pica VS instructions to pointers in the emitted code
+ std::array<const u8*, 1024> code_ptr;
+
+ /// Offsets in code where a return needs to be inserted
+ std::set<unsigned> return_offsets;
+
+ unsigned last_program_counter; ///< Offset of the most recent instruction decoded
+ unsigned program_counter; ///< Offset of the next instruction to decode
+ bool looping = false; ///< True if compiling a loop, used to check for nested loops
- /// Set to true if currently in a loop, used to check for the existence of nested loops
- bool looping = false;
+ /// Branches that need to be fixed up once the entire shader program is compiled
+ std::vector<std::pair<Gen::FixupBranch, unsigned>> fixup_branches;
};
} // Shader