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fix: improve perf of instructions w/ rotr

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This commit is contained in:
Rekai Nyangadzayi Musuka
2022-03-16 22:28:24 -03:00
parent 1921218c7b
commit 39ab363afa
7 changed files with 33 additions and 13 deletions
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5
src/cpu/arm/half_signed_data_transfer.zig
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@@ -5,6 +5,7 @@ const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi;
const InstrFn = @import("../../cpu.zig").ArmInstrFn;
const sext = @import("../../util.zig").sext;
const rotr = @import("../../util.zig").rotr;
pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I: bool, comptime W: bool, comptime L: bool) InstrFn {
return struct {
@@ -38,7 +39,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
0b01 => {
// LDRH
const value = bus.read16(address & 0xFFFF_FFFE);
result = std.math.rotr(u32, value, 8 * (address & 1));
result = rotr(u32, value, 8 * (address & 1));
},
0b10 => {
// LDRSB
@@ -52,7 +53,7 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I:
break :blk sext(16, bus.read16(address));
};
result = std.math.rotr(u32, value, 8 * (address & 1));
result = rotr(u32, value, 8 * (address & 1));
},
0b00 => unreachable, // SWP
}