Looking at this PR I noticed that there were other potential issues with
the implementation of this function, so I've essentially rewritten it.
We now far more consistently use gen_(high/low)part, and avoid
dereferencing REGNO when we don't have a register src.
R.
2014-01-16 Richard Earnshaw <rearn...@arm.com>
PR target/59780
* aarch64.c (aarch64_split_128bit_move): Don't lookup REGNO on
non-register objects. Use gen_(high/low)part more consistently.
Fix assertions.--- aarch64.c (revision 206647)
+++ aarch64.c (local)
@@ -680,90 +680,82 @@ aarch64_emit_move (rtx dest, rtx src)
: emit_move_insn_1 (dest, src));
}
+/* Split a 128-bit move operation into two 64-bit move operations,
+ taking care to handle partial overlap of register to register
+ copies. Special cases are needed when moving between GP regs and
+ FP regs. SRC can be a register, constant or memory; DST a register
+ or memory. If either operand is memory it must not have any side
+ effects. */
void
aarch64_split_128bit_move (rtx dst, rtx src)
{
- rtx low_dst;
+ rtx dst_lo, dst_hi;
+ rtx src_lo, src_hi;
- enum machine_mode src_mode = GET_MODE (src);
- enum machine_mode dst_mode = GET_MODE (dst);
- int src_regno = REGNO (src);
- int dst_regno = REGNO (dst);
+ enum machine_mode mode = GET_MODE (dst);
- gcc_assert (dst_mode == TImode || dst_mode == TFmode);
+ gcc_assert (mode == TImode || mode == TFmode);
+ gcc_assert (!(side_effects_p (src) || side_effects_p (dst)));
+ gcc_assert (mode == GET_MODE (src) || GET_MODE (src) == VOIDmode);
if (REG_P (dst) && REG_P (src))
{
- gcc_assert (src_mode == TImode || src_mode == TFmode);
+ int src_regno = REGNO (src);
+ int dst_regno = REGNO (dst);
- /* Handle r -> w, w -> r. */
+ /* Handle FP <-> GP regs. */
if (FP_REGNUM_P (dst_regno) && GP_REGNUM_P (src_regno))
{
- switch (src_mode) {
- case TImode:
- emit_insn
- (gen_aarch64_movtilow_di (dst, gen_lowpart (word_mode, src)));
- emit_insn
- (gen_aarch64_movtihigh_di (dst, gen_highpart (word_mode, src)));
- return;
- case TFmode:
- emit_insn
- (gen_aarch64_movtflow_di (dst, gen_lowpart (word_mode, src)));
- emit_insn
- (gen_aarch64_movtfhigh_di (dst, gen_highpart (word_mode, src)));
- return;
- default:
- gcc_unreachable ();
- }
+ src_lo = gen_lowpart (word_mode, src);
+ src_hi = gen_highpart (word_mode, src);
+
+ if (mode == TImode)
+ {
+ emit_insn (gen_aarch64_movtilow_di (dst, src_lo));
+ emit_insn (gen_aarch64_movtihigh_di (dst, src_hi));
+ }
+ else
+ {
+ emit_insn (gen_aarch64_movtflow_di (dst, src_lo));
+ emit_insn (gen_aarch64_movtfhigh_di (dst, src_hi));
+ }
+ return;
}
else if (GP_REGNUM_P (dst_regno) && FP_REGNUM_P (src_regno))
{
- switch (src_mode) {
- case TImode:
- emit_insn
- (gen_aarch64_movdi_tilow (gen_lowpart (word_mode, dst), src));
- emit_insn
- (gen_aarch64_movdi_tihigh (gen_highpart (word_mode, dst), src));
- return;
- case TFmode:
- emit_insn
- (gen_aarch64_movdi_tflow (gen_lowpart (word_mode, dst), src));
- emit_insn
- (gen_aarch64_movdi_tfhigh (gen_highpart (word_mode, dst), src));
- return;
- default:
- gcc_unreachable ();
- }
+ dst_lo = gen_lowpart (word_mode, dst);
+ dst_hi = gen_highpart (word_mode, dst);
+
+ if (mode == TImode)
+ {
+ emit_insn (gen_aarch64_movdi_tilow (dst_lo, src));
+ emit_insn (gen_aarch64_movdi_tihigh (dst_hi, src));
+ }
+ else
+ {
+ emit_insn (gen_aarch64_movdi_tflow (dst_lo, src));
+ emit_insn (gen_aarch64_movdi_tfhigh (dst_hi, src));
+ }
+ return;
}
- /* Fall through to r -> r cases. */
}
- switch (dst_mode) {
- case TImode:
- low_dst = gen_lowpart (word_mode, dst);
- if (REG_P (low_dst)
- && reg_overlap_mentioned_p (low_dst, src))
- {
- aarch64_emit_move (gen_highpart (word_mode, dst),
- gen_highpart_mode (word_mode, TImode, src));
- aarch64_emit_move (low_dst, gen_lowpart (word_mode, src));
- }
- else
- {
- aarch64_emit_move (low_dst, gen_lowpart (word_mode, src));
- aarch64_emit_move (gen_highpart (word_mode, dst),
- gen_highpart_mode (word_mode, TImode, src));
- }
- return;
- case TFmode:
- emit_move_insn (gen_rtx_REG (DFmode, dst_regno),
- gen_rtx_REG (DFmode, src_regno));
- emit_move_insn (gen_rtx_REG (DFmode, dst_regno + 1),
- gen_rtx_REG (DFmode, src_regno + 1));
- return;
- default:
- gcc_unreachable ();
- }
+ dst_lo = gen_lowpart (word_mode, dst);
+ dst_hi = gen_highpart (word_mode, dst);
+ src_lo = gen_lowpart (word_mode, src);
+ src_hi = gen_highpart_mode (word_mode, mode, src);
+
+ /* At most one pairing may overlap. */
+ if (reg_overlap_mentioned_p (dst_lo, src_hi))
+ {
+ aarch64_emit_move (dst_hi, src_hi);
+ aarch64_emit_move (dst_lo, src_lo);
+ }
+ else
+ {
+ aarch64_emit_move (dst_lo, src_lo);
+ aarch64_emit_move (dst_hi, src_hi);
+ }
}
bool
