[Bug target/108787] [13 Regression] libsodium miscompilation on power9 starting with r13-2107

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108787

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/config/rs6000/rs6000.md.jj      2023-01-16 11:52:16.036734757 +0100
+++ gcc/config/rs6000/rs6000.md 2023-02-14 18:53:25.071014954 +0100
@@ -3231,20 +3231,26 @@
        (plus:TI
          (mult:TI (any_extend:TI (match_operand:DI 1 "gpc_reg_operand"))
                   (any_extend:TI (match_operand:DI 2 "gpc_reg_operand")))
-         (any_extend:TI (match_operand:DI 3 "gpc_reg_operand"))))]
+         (match_operand:TI 3 "gpc_reg_operand")))]
   "TARGET_MADDLD && TARGET_POWERPC64"
 {
   rtx op0_lo = gen_rtx_SUBREG (DImode, operands[0], BYTES_BIG_ENDIAN ? 8 : 0);
   rtx op0_hi = gen_rtx_SUBREG (DImode, operands[0], BYTES_BIG_ENDIAN ? 0 : 8);
+  rtx op3_lo = gen_rtx_SUBREG (DImode, operands[3], BYTES_BIG_ENDIAN ? 8 : 0);
+  rtx op3_hi = gen_rtx_SUBREG (DImode, operands[3], BYTES_BIG_ENDIAN ? 0 : 8);
+  rtx hi_temp = gen_reg_rtx (DImode);

-  emit_insn (gen_maddlddi4 (op0_lo, operands[1], operands[2], operands[3]));
+  emit_insn (gen_maddlddi4 (op0_lo, operands[1], operands[2], op3_lo));

   if (BYTES_BIG_ENDIAN)
-    emit_insn (gen_<u>madddi4_highpart (op0_hi, operands[1], operands[2],
-                                       operands[3]));
+    emit_insn (gen_<u>madddi4_highpart (hi_temp, operands[1], operands[2],
+                                       op3_lo));
   else
-    emit_insn (gen_<u>madddi4_highpart_le (op0_hi, operands[1], operands[2],
-                                          operands[3]));
+    emit_insn (gen_<u>madddi4_highpart_le (hi_temp, operands[1], operands[2],
+                                          op3_lo));
+
+  emit_insn (gen_adddi3 (op0_hi, hi_temp, op3_hi));
+
   DONE;
 })


seems to fix this, but I have yet to check if it is the right thing also for
the signed case.