From: Markus Trippelsdorf Date: Wed, 30 Nov 2016 07:30:55 +0000 (+0000) Subject: Fix PR78588 - rtlanal.c:5210:38: runtime error: shift exponent 4294967295 is too... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ced17de64000713e99af200bb9ff468b907ec1f9;p=gcc.git Fix PR78588 - rtlanal.c:5210:38: runtime error: shift exponent 4294967295 is too large for 64-bit type Building gcc with -fsanitize=undefined shows: rtlanal.c:5210:38: runtime error: shift exponent 4294967295 is too large for 64-bit type 'long unsigned int' This happens because if_then_else_cond() in combine.c calls num_sign_bit_copies() in rtlanal.c with mode==BLKmode. 5205 bitwidth = GET_MODE_PRECISION (mode); 5206 if (bitwidth > HOST_BITS_PER_WIDE_INT) 5207 return 1; 5208 5209 nonzero = nonzero_bits (x, mode); 5210 return nonzero & (HOST_WIDE_INT_1U << (bitwidth - 1)) 5211 ? 1 : bitwidth - floor_log2 (nonzero) - 1; This causes (bitwidth - 1) to wrap around. PR rtl-optimization/78588 * combine.c (if_then_else_cond): Also guard against BLKmode. * rtlanal.c (num_sign_bit_copies1): Add assert. From-SVN: r242997 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a5b191b6ed2..48862fbdddf 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-11-30 Markus Trippelsdorf + + PR rtl-optimization/78588 + * combine.c (if_then_else_cond): Also guard against BLKmode. + * rtlanal.c (num_sign_bit_copies1): Add assert. + 2016-11-29 Jeff Law * common/config/arc/arc-common.c (arc_handle_option): Remove unused diff --git a/gcc/combine.c b/gcc/combine.c index 22fb7a97653..a32a0ecc72f 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -9176,7 +9176,7 @@ if_then_else_cond (rtx x, rtx *ptrue, rtx *pfalse) /* If X is known to be either 0 or -1, those are the true and false values when testing X. */ else if (x == constm1_rtx || x == const0_rtx - || (mode != VOIDmode + || (mode != VOIDmode && mode != BLKmode && num_sign_bit_copies (x, mode) == GET_MODE_PRECISION (mode))) { *ptrue = constm1_rtx, *pfalse = const0_rtx; diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c index 4e4eb2ef345..60550adb7cf 100644 --- a/gcc/rtlanal.c +++ b/gcc/rtlanal.c @@ -4840,6 +4840,8 @@ num_sign_bit_copies1 (const_rtx x, machine_mode mode, const_rtx known_x, if (mode == VOIDmode) mode = GET_MODE (x); + gcc_checking_assert (mode != BLKmode); + if (mode == VOIDmode || FLOAT_MODE_P (mode) || FLOAT_MODE_P (GET_MODE (x)) || VECTOR_MODE_P (GET_MODE (x)) || VECTOR_MODE_P (mode)) return 1;