[Bug target/102239] powerpc suboptimal boolean test of contiguous bits

[luoxhu at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102239

--- Comment #4 from luoxhu at gcc dot gnu.org ---
Simply adjust the sequence of dot instruction could produce expected code, is
this correct?


foo:
.LFB0:
        .cfi_startproc
        rldicr. 3,3,29,1
        beq 0,.L2
#APP
 # 10 "pr102239.c" 1
        # if
 # 0 "" 2
#NO_APP
        blr
        .p2align 4,,15
.L2:
#APP
 # 12 "pr102239.c" 1
        # else
 # 0 "" 2
#NO_APP
        blr



 git diff
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index c9ce0550df1..2f0b5992bbf 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -11749,9 +11749,9 @@ rs6000_emit_2insn_and (machine_mode mode, rtx
*operands, bool expand, int dot)
        {
          rtx tmp = gen_rtx_ASHIFT (mode, operands[1], GEN_INT (shift));
          tmp = gen_rtx_AND (mode, tmp, GEN_INT (val << shift));
-         emit_move_insn (operands[0], tmp);
-         tmp = gen_rtx_LSHIFTRT (mode, operands[0], GEN_INT (shift));
          rs6000_emit_dot_insn (operands[0], tmp, dot, dot ? operands[3] : 0);
+         tmp = gen_rtx_LSHIFTRT (mode, operands[0], GEN_INT (shift));
+         emit_move_insn (operands[0], tmp);
        }
       return;
     }