re PR rtl-optimization/89795 (wrong code with -O2 -fno-dce…

re PR rtl-optimization/89795 (wrong code with -O2 -fno-dce -fno-forward-propagate -fno-sched-pressure)

	PR rtl-optimization/89795
	* rtlanal.c (nonzero_bits1) <SUBREG>: Do not propagate results from
	inner REGs to paradoxical SUBREGs if WORD_REGISTER_OPERATIONS is set.

From-SVN: r275635

gcc/ChangeLog

+2019-09-11  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/89795
+	* rtlanal.c (nonzero_bits1) <SUBREG>: Do not propagate results from
+	inner REGs to paradoxical SUBREGs if WORD_REGISTER_OPERATIONS is set.
+
 2019-09-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/91723

gcc/rtlanal.c

@@ -4819,7 +4819,7 @@ nonzero_bits1 (const_rtx x, scalar_int_mode mode, const_rtx known_x,
 	       || ((extend_op = load_extend_op (inner_mode)) == SIGN_EXTEND
 		   ? val_signbit_known_set_p (inner_mode, nonzero)
 		   : extend_op != ZERO_EXTEND)
-	       || (!MEM_P (SUBREG_REG (x)) && !REG_P (SUBREG_REG (x))))
+	       || !MEM_P (SUBREG_REG (x)))
 	      && xmode_width > inner_width)
 	    nonzero
 	      |= (GET_MODE_MASK (GET_MODE (x)) & ~GET_MODE_MASK (inner_mode));

gcc/testsuite/ChangeLog

+2019-09-11  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.target/sparc/20161111-1.c: XFAIL redundant zero-extension test.
+
 2019-09-11  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/91723

gcc/testsuite/gcc.target/sparc/20161111-1.c

@@ -14,4 +14,4 @@ unsigned char ee_isdigit2(unsigned int i)
   return retval;
 }
 
-/* { dg-final { scan-assembler-not "and\t%" } } */
+/* { dg-final { scan-assembler-not "and\t%" { xfail *-*-* } } } */