diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 96c2aac..e8134ce 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -31,7 +31,7 @@ jobs:
         if: matrix.TARGET.OS == 'ubuntu-20.04'
         run: |
           sudo apt-get update
-          sudo apt-get install -y build-essential bison file gperf gcc gcc-multilib
+          sudo apt-get install -y build-essential bison file gperf gcc gcc-multilib autoconf
       - name: Configure for mips
         shell: bash
         run: |
diff --git a/.gitignore b/.gitignore
index 6aa69e0..c9b4849 100644
--- a/.gitignore
+++ b/.gitignore
@@ -135,3 +135,10 @@ gcc/tree-check.h
 gcc/unprotoize
 gcc/xgcc
 gcc/xlimits.h
+
+gcc/autom4te.cache/requests
+gcc/autom4te.cache/output.*
+gcc/autom4te.cache/traces.*
+gcc/config.in~
+gcc/config.bak
+gcc/configure~
diff --git a/gcc/cse.c b/gcc/cse.c
index cfcc4fa..3c00b10 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -5602,7 +5602,7 @@ fold_rtx (x, insn)
 	     hence not save anything) or be incorrect.  */
 	  if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT
 	      && INTVAL (const_arg1) < 0
-	      && - INTVAL (const_arg1) >= 0
+	      && (-INTVAL (const_arg1) >> 0x1f) >= 0
 	      && GET_CODE (folded_arg1) == REG)
 	    {
 	      rtx new_const = GEN_INT (- INTVAL (const_arg1));