From: Guo Jie <guojie@loongson.cn>
Date: Thu, 23 Nov 2023 03:05:56 +0000 (+0800)
Subject: LoongArch: Fix runtime error in a gcc build with --with-build-config=bootstrap-ubsan
X-Git-Tag: basepoints/gcc-15~4275
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8b9d0e8cf482287b6c37b5a268d0eb2d0a964561;p=thirdparty%2Fgcc.git

LoongArch: Fix runtime error in a gcc build with --with-build-config=bootstrap-ubsan

gcc/ChangeLog:

	* config/loongarch/loongarch.cc (loongarch_split_plus_constant):
	avoid left shift of negative value -0x8000.
---

diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index c95fc83362e9..d3896d72bc2e 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -4269,7 +4269,7 @@ loongarch_split_plus_constant (rtx *op, machine_mode mode)
   else if (loongarch_addu16i_imm12_operand_p (v, mode))
     a = (v & ~HWIT_UC_0xFFF) + ((v & 0x800) << 1);
   else if (mode == DImode && DUAL_ADDU16I_OPERAND (v))
-    a = (v > 0 ? 0x7fff : -0x8000) << 16;
+    a = (v > 0 ? 0x7fff0000 : ~0x7fffffff);
   else
     gcc_unreachable ();