Index: simplify-rtx.c =================================================================== --- simplify-rtx.c (revision 191808) +++ simplify-rtx.c (working copy) @@ -5689,6 +5689,28 @@ simplify_subreg (enum machine_mode outermode, rtx return CONST0_RTX (outermode); } + /* Simplify (subreg:SI (op:DI ((x:DI) (y:DI)), 0) + to (op:SI (subreg:SI (x:DI) 0) (subreg:SI (x:DI) 0)), where + the outer subreg is effectively a truncation to the original mode. */ + if ((GET_CODE (op) == PLUS + || GET_CODE (op) == MINUS + || GET_CODE (op) == MULT) + && SCALAR_INT_MODE_P (outermode) + && SCALAR_INT_MODE_P (innermode) + && GET_MODE_PRECISION (outermode) < GET_MODE_PRECISION (innermode) + && byte == subreg_lowpart_offset (outermode, innermode)) + { + rtx op0 = simplify_gen_subreg (outermode, XEXP (op, 0), + innermode, byte); + if (op0) + { + rtx op1 = simplify_gen_subreg (outermode, XEXP (op, 1), + innermode, byte); + if (op1) + return simplify_gen_binary (GET_CODE (op), outermode, op0, op1); + } + } + /* Simplify (subreg:QI (lshiftrt:SI (sign_extend:SI (x:QI)) C), 0) into to (ashiftrt:QI (x:QI) C), where C is a suitable small constant and the outer subreg is effectively a truncation to the original mode. */ Index: testsuite/gcc.target/i386/pr54457.c =================================================================== --- testsuite/gcc.target/i386/pr54457.c (revision 0) +++ testsuite/gcc.target/i386/pr54457.c (working copy) @@ -0,0 +1,11 @@ +/* { dg-do compile { target { ! { ia32 } } } } */ +/* { dg-options "-O2 -mx32 -maddress-mode=short" } */ + +extern char array[40]; + +char foo (long long position) +{ + return array[position + 1]; +} + +/* { dg-final { scan-assembler-not "add\[lq\]?\[^\n\]*1" } } */