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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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4
src/cpu/arm/psr_transfer.zig
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@@ -7,6 +7,8 @@ const PSR = @import("../../cpu.zig").PSR;
const log = std.log.scoped(.PsrTransfer);
const rotr = @import("../../util.zig").rotr;
pub fn psrTransfer(comptime I: bool, comptime R: bool, comptime kind: u2) InstrFn {
return struct {
fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void {
@@ -22,7 +24,7 @@ pub fn psrTransfer(comptime I: bool, comptime R: bool, comptime kind: u2) InstrF
// MSR
const field_mask = @truncate(u4, opcode >> 16 & 0xF);
const rm_idx = opcode & 0xF;
const right = if (I) std.math.rotr(u32, opcode & 0xFF, (opcode >> 8 & 0xF) << 1) else cpu.r[rm_idx];
const right = if (I) rotr(u32, opcode & 0xFF, (opcode >> 8 & 0xF) << 1) else cpu.r[rm_idx];
if (R and !cpu.hasSPSR()) log.warn("Tried to write to SPSR in User/System Mode", .{});