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[a64] Avoid LoadV128Const scratch-memory usage

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Use the provided scratch register-index, defaults to W0/X0, and insert 64-bit elements directly into the vector-register rather than writing/reading to scratch memory.
This commit is contained in:
Wunkolo
2026-03-23 19:03:10 -07:00
committed by Heel
parent a045586e8e
commit 39706a0974
1 changed files with 13 additions and 15 deletions
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28
src/xenia/cpu/backend/a64/a64_seq_util.h
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@@ -45,7 +45,9 @@ inline void EmitWithVmxFpcr(A64Emitter& e, Fn&& emit_op) {
}
// Load a compile-time vec128_t constant into a NEON register.
inline void LoadV128Const(A64Emitter& e, int vreg_idx, const vec128_t& val) {
// May clobber the provided GPR scratch-register
inline void LoadV128Const(A64Emitter& e, int vreg_idx, const vec128_t& val,
int gpr_scratch_idx = 0) {
if (!val.low && !val.high) {
// 0000...
e.movi(VReg2D(vreg_idx), 0);
@@ -82,8 +84,8 @@ inline void LoadV128Const(A64Emitter& e, int vreg_idx, const vec128_t& val) {
} else if ((splat_u16 & 0x00'FF) == 0) {
e.movi(VReg(vreg_idx).h8, static_cast<uint8_t>(splat_u16 >> 8), LSL, 8);
} else {
e.movz(e.w0, splat_u16);
e.dup(VReg(vreg_idx).h8, e.w0);
e.movz(WReg(gpr_scratch_idx), splat_u16);
e.dup(VReg(vreg_idx).h8, WReg(gpr_scratch_idx));
}
return;
}
@@ -108,8 +110,8 @@ inline void LoadV128Const(A64Emitter& e, int vreg_idx, const vec128_t& val) {
e.movi(VReg(vreg_idx).s4, static_cast<uint8_t>(splat_u32 >> 24), LSL,
24);
} else {
e.mov(e.w0, splat_u32);
e.dup(VReg(vreg_idx).s4, e.w0);
e.mov(WReg(gpr_scratch_idx), splat_u32);
e.dup(VReg(vreg_idx).s4, WReg(gpr_scratch_idx));
}
return;
}
@@ -117,20 +119,16 @@ inline void LoadV128Const(A64Emitter& e, int vreg_idx, const vec128_t& val) {
const bool all_equal_u64 = val.low == val.high;
const uint64_t splat_u64 = val.u64[0];
if (all_equal_u64) {
e.mov(e.x0, splat_u64);
e.dup(VReg(vreg_idx).d2, e.x0);
e.mov(XReg(gpr_scratch_idx), splat_u64);
e.dup(VReg(vreg_idx).d2, XReg(gpr_scratch_idx));
return;
}
}
e.mov(e.x0, val.low);
e.mov(e.x1, val.high);
e.stp(e.x0, e.x1,
Xbyak_aarch64::ptr(e.sp,
static_cast<int32_t>(StackLayout::GUEST_SCRATCH)));
e.ldr(QReg(vreg_idx),
Xbyak_aarch64::ptr(e.sp,
static_cast<int32_t>(StackLayout::GUEST_SCRATCH)));
e.mov(XReg(gpr_scratch_idx), val.low);
e.fmov(DReg(vreg_idx), XReg(gpr_scratch_idx));
e.mov(XReg(gpr_scratch_idx), val.high);
e.ins(VReg(vreg_idx).d2[1], XReg(gpr_scratch_idx));
}
// Resolve a V128 operand to a register index, loading constants into