===================================================================
@@ -49,6 +49,7 @@
#include "context.h"
#include "tree-pass.h"
#include "print-rtl.h"
+#include "rtl-iter.h"
/* This file should be included last. */
#include "target-def.h"
@@ -12823,6 +12824,34 @@ avr_convert_to_type (tree type, tree exp
}
+/* Implement `TARGET_LEGITIMATE_COMBINED_INSN'. */
+
+/* PR78883: Filter out paradoxical SUBREGs of MEM which are not handled
+ properly by following passes. As INSN_SCHEDULING is off and hence
+ general_operand accepts such expressions, ditch them now. */
+
+static bool
+avr_legitimate_combined_insn (rtx_insn *insn)
+{
+ subrtx_iterator::array_type array;
+
+ FOR_EACH_SUBRTX (iter, array, PATTERN (insn), NONCONST)
+ {
+ const_rtx op = *iter;
+
+ if (SUBREG_P (op)
+ && MEM_P (SUBREG_REG (op))
+ && (GET_MODE_SIZE (GET_MODE (op))
+ > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op)))))
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+
/* PR63633: The middle-end might come up with hard regs as input operands.
RMASK is a bit mask representing a subset of hard registers R0...R31:
@@ -14364,6 +14393,9 @@ avr_fold_builtin (tree fndecl, int n_arg
#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
avr_use_by_pieces_infrastructure_p
+#undef TARGET_LEGITIMATE_COMBINED_INSN
+#define TARGET_LEGITIMATE_COMBINED_INSN avr_legitimate_combined_insn
+
struct gcc_target targetm = TARGET_INITIALIZER;
===================================================================
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+int foo (int *p)
+{
+ int i;
+ for (i = 0; i < 5; i++)
+ {
+ if (p[i] & 1)
+ return i;
+ }
+ return -1;
+}