From 7fdf991097649f17fde7e91b16de3817f4df6abb Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Thu, 24 Oct 2019 00:57:19 -0400
Subject: [PATCH] shader_bytecode: Make Matcher constexpr capable
Greatly shrinks the amount of generated code for GetDecodeTable().
Collapses an assembly output of 9000+ lines down to ~3621 with Clang,
and 6513 down to ~2616 with GCC, given it's now allowed to construct all
the entries as a sequence of constant data.
---
src/video_core/engines/shader_bytecode.h | 26 ++++++++++++------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/src/video_core/engines/shader_bytecode.h b/src/video_core/engines/shader_bytecode.h
index 7a6355ce2b..d3d05a8665 100644
--- a/src/video_core/engines/shader_bytecode.h
+++ b/src/video_core/engines/shader_bytecode.h
@@ -574,7 +574,7 @@ enum class ShuffleOperation : u64 {
};
union Instruction {
- Instruction& operator=(const Instruction& instr) {
+ constexpr Instruction& operator=(const Instruction& instr) {
value = instr.value;
return *this;
}
@@ -1760,22 +1760,22 @@ public:
class Matcher {
public:
- Matcher(const char* const name, u16 mask, u16 expected, OpCode::Id id, OpCode::Type type)
+ constexpr Matcher(const char* const name, u16 mask, u16 expected, Id id, Type type)
: name{name}, mask{mask}, expected{expected}, id{id}, type{type} {}
- const char* GetName() const {
+ constexpr const char* GetName() const {
return name;
}
- u16 GetMask() const {
+ constexpr u16 GetMask() const {
return mask;
}
- Id GetId() const {
+ constexpr Id GetId() const {
return id;
}
- Type GetType() const {
+ constexpr Type GetType() const {
return type;
}
@@ -1784,7 +1784,7 @@ public:
* @param instruction The instruction to test
* @returns true if the given instruction matches.
*/
- bool Matches(u16 instruction) const {
+ constexpr bool Matches(u16 instruction) const {
return (instruction & mask) == expected;
}
@@ -1818,7 +1818,7 @@ private:
* A '0' in a bitstring indicates that a zero must be present at that bit position.
* A '1' in a bitstring indicates that a one must be present at that bit position.
*/
- static auto GetMaskAndExpect(const char* const bitstring) {
+ static constexpr auto GetMaskAndExpect(const char* const bitstring) {
u16 mask = 0, expect = 0;
for (std::size_t i = 0; i < opcode_bitsize; i++) {
const std::size_t bit_position = opcode_bitsize - i - 1;
@@ -1835,15 +1835,15 @@ private:
break;
}
}
- return std::make_tuple(mask, expect);
+ return std::make_pair(mask, expect);
}
public:
/// Creates a matcher that can match and parse instructions based on bitstring.
- static auto GetMatcher(const char* const bitstring, OpCode::Id op, OpCode::Type type,
- const char* const name) {
- const auto mask_expect = GetMaskAndExpect(bitstring);
- return Matcher(name, std::get<0>(mask_expect), std::get<1>(mask_expect), op, type);
+ static constexpr auto GetMatcher(const char* const bitstring, Id op, Type type,
+ const char* const name) {
+ const auto [mask, expected] = GetMaskAndExpect(bitstring);
+ return Matcher(name, mask, expected, op, type);
}
};