re PR middle-end/61158 (negative shift at fold-const.c:12095)
PR tree-optimization/61158 * fold-const.c (fold_binary_loc): If X is zero-extended and shiftc >= prec, make sure zerobits is all ones instead of invoking undefined behavior. * gcc.dg/pr61158.c: New test. From-SVN: r210467
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2014-05-15 Jakub Jelinek <jakub@redhat.com>
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PR tree-optimization/61158
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* fold-const.c (fold_binary_loc): If X is zero-extended and
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shiftc >= prec, make sure zerobits is all ones instead of
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invoking undefined behavior.
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2014-05-15 Zhenqiang Chen <zhenqiang.chen@linaro.org>
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* regcprop.h: New file.
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* regcprop.c (skip_debug_insn_p): New decl.
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(replace_oldest_value_reg): Check skip_debug_insn_p.
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(copyprop_hardreg_forward_bb_without_debug_insn.): New function.
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* shrink-wrap.c: include regcprop.h
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(prepare_shrink_wrap):
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Call copyprop_hardreg_forward_bb_without_debug_insn.
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(copyprop_hardreg_forward_bb_without_debug_insn): New function.
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* shrink-wrap.c: Include regcprop.h.
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(prepare_shrink_wrap): Call
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copyprop_hardreg_forward_bb_without_debug_insn.
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2014-05-15 Zhenqiang Chen <zhenqiang.chen@linaro.org>
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@ -11972,11 +11972,17 @@ fold_binary_loc (location_t loc,
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/* See if we can shorten the right shift. */
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if (shiftc < prec)
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shift_type = inner_type;
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/* Otherwise X >> C1 is all zeros, so we'll optimize
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it into (X, 0) later on by making sure zerobits
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is all ones. */
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}
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}
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zerobits = ~(unsigned HOST_WIDE_INT) 0;
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zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
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zerobits <<= prec - shiftc;
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if (shiftc < prec)
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{
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zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
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zerobits <<= prec - shiftc;
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}
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/* For arithmetic shift if sign bit could be set, zerobits
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can contain actually sign bits, so no transformation is
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possible, unless MASK masks them all away. In that
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@ -11994,7 +12000,7 @@ fold_binary_loc (location_t loc,
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/* ((X << 16) & 0xff00) is (X, 0). */
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if ((mask & zerobits) == mask)
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return omit_one_operand_loc (loc, type,
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build_int_cst (type, 0), arg0);
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build_int_cst (type, 0), arg0);
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newmask = mask | zerobits;
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if (newmask != mask && (newmask & (newmask + 1)) == 0)
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@ -1,3 +1,8 @@
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2014-05-15 Jakub Jelinek <jakub@redhat.com>
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PR tree-optimization/61158
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* gcc.dg/pr61158.c: New test.
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2014-05-15 Andreas Schwab <schwab@suse.de>
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* obj-c++.dg/exceptions-3.mm: Remove check for message no longer
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12
gcc/testsuite/gcc.dg/pr61158.c
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12
gcc/testsuite/gcc.dg/pr61158.c
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@ -0,0 +1,12 @@
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/* PR tree-optimization/61158 */
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/* { dg-do compile } */
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/* { dg-options "-O2 -fdump-tree-original" } */
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unsigned long long
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foo (unsigned int x)
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{
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return ((unsigned long long) x & 0x00ff000000000000ULL) >> 40;
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}
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/* { dg-final { scan-tree-dump "return 0;" "original" { target { ilp32 || lp64 } } } } */
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/* { dg-final { cleanup-tree-dump "original" } } */
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