From: Kito Cheng <kito.ch...@gmail.com>
ChangeLog:
gcc/
* config/nds32/nds32-md-auxiliary.c (nds32_split_ashiftdi3):
Fix wrong code gen with large shift amount.
---
gcc/config/nds32/nds32-md-auxiliary.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/gcc/config/nds32/nds32-md-auxiliary.c
b/gcc/config/nds32/nds32-md-auxiliary.c
index 33844be..71fa421 100644
--- a/gcc/config/nds32/nds32-md-auxiliary.c
+++ b/gcc/config/nds32/nds32-md-auxiliary.c
@@ -3304,15 +3304,22 @@ nds32_split_ashiftdi3 (rtx dst, rtx src, rtx
shiftamount)
ext_start = gen_reg_rtx (SImode);
/*
- if (shiftamount < 32)
+ # In fact, we want to check shift amonut is great than or equal 32,
+ # but in some corner case, the shift amount might be very large value,
+ # however we've defined SHIFT_COUNT_TRUNCATED, so GCC think we've
+ # handle that correctly without any truncate.
+ # so check the the condition of (shiftamount & 32) is most
+ # safe way to do.
+ if (shiftamount & 32)
+ dst_low_part = 0
+ dst_high_part = src_low_part << shiftamount & 0x1f
+ else
dst_low_part = src_low_part << shiftamout
dst_high_part = wext (src, 32 - shiftamount)
# wext can't handle wext (src, 32) since it's only take rb[0:4]
# for extract.
dst_high_part = shiftamount == 0 ? src_high_part : dst_high_part
- else
- dst_low_part = 0
- dst_high_part = src_low_part << shiftamount & 0x1f
+
*/
emit_insn (gen_subsi3 (ext_start,
@@ -3331,11 +3338,11 @@ nds32_split_ashiftdi3 (rtx dst, rtx src, rtx
shiftamount)
emit_insn (gen_ashlsi3 (dst_high_part_g32, src_low_part,
new_shift_amout));
- emit_insn (gen_slt_compare (select_reg, shiftamount, GEN_INT (32)));
+ emit_insn (gen_andsi3 (select_reg, shiftamount, GEN_INT (32)));
- emit_insn (gen_cmovnsi (dst_low_part, select_reg,
+ emit_insn (gen_cmovzsi (dst_low_part, select_reg,
dst_low_part_l32, dst_low_part_g32));
- emit_insn (gen_cmovnsi (dst_high_part, select_reg,
+ emit_insn (gen_cmovzsi (dst_high_part, select_reg,
dst_high_part_l32, dst_high_part_g32));
}
}
--
1.8.3.1
