From 85b242968bf34b60ff7ef0fcb8ac94eacfa762a0 Mon Sep 17 00:00:00 2001 From: Kito Cheng Date: Tue, 16 Apr 2019 09:27:31 +0000 Subject: [NDS32] Fix nds32_split_ashiftdi3 with large shift amount. gcc/ * config/nds32/nds32-md-auxiliary.c (nds32_split_ashiftdi3): Fix wrong code gen with large shift amount. Co-Authored-By: Shiva Chen From-SVN: r270383 --- gcc/config/nds32/nds32-md-auxiliary.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'gcc/config/nds32') diff --git a/gcc/config/nds32/nds32-md-auxiliary.c b/gcc/config/nds32/nds32-md-auxiliary.c index 35fcc64..eadd841 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)); } } -- cgit v1.1