[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.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@270383 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 083864ec66c614a947e1148993011c3139477a33..610a25f3fe1596ba3c6769ac0459ced5ac933292 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-04-16  Kito Cheng  <kito.cheng@gmail.com>
+           Shiva Chen  <shiva0217@gmail.com>
+
+       * config/nds32/nds32-md-auxiliary.c (nds32_split_ashiftdi3): Fix wrong
+       code gen with large shift amount.
+
 2019-04-16  Chung-Ju Wu  <jasonwucj@gmail.com>
 
        * config/nds32/nds32-pipelines-auxiliary.c (wext_odd_dep_p): Handle

diff --git a/gcc/config/nds32/nds32-md-auxiliary.c b/gcc/config/nds32/nds32-md-auxiliary.c
index 35fcc64511f52d394fda5cabbd6e97153ffa4d14..eadd8417878be719ea4f59c18996dc74b72b8b9e 100644 (file)
--- 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));
     }
 }