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fold: Remove (rrotate (rrotate A CST) CST) folding [PR117492]
This removes an (broken) simplification from fold which is already handled in match. The reason why it was broken is because of the use of wi::to_wide on the RHS of the rotate which could be 2 different types even though the LHS was the same type. Since it is already handled in match (by the patterns for `Turn (a OP c1) OP c2 into a OP (c1+c2).`). It can be removed without losing any optimizations. Bootstrapped and tested on x86_64-linux-gnu. PR middle-end/117492 gcc/ChangeLog: * fold-const.cc (fold_binary_loc): Remove `Two consecutive rotates adding up to the some integer` simplifcation. gcc/testsuite/ChangeLog: * gcc.dg/torture/pr117492-1.c: New test. Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
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@ -12530,16 +12530,6 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
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arg01, arg1));
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}
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/* Two consecutive rotates adding up to the some integer
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multiple of the precision of the type can be ignored. */
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if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
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&& TREE_CODE (arg0) == RROTATE_EXPR
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&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
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&& wi::umod_trunc (wi::to_wide (arg1)
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+ wi::to_wide (TREE_OPERAND (arg0, 1)),
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prec) == 0)
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return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
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return NULL_TREE;
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case MIN_EXPR:
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16
gcc/testsuite/gcc.dg/torture/pr117492-1.c
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16
gcc/testsuite/gcc.dg/torture/pr117492-1.c
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@ -0,0 +1,16 @@
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/* { dg-do compile } */
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/* PR middle-end/117492 */
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/* This code would ICE in fold due to code which was using wi::to_wide with different types
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and adding them. */
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typedef unsigned u;
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u
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foo(u x)
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{
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return
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__builtin_stdc_rotate_left((unsigned)
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__builtin_stdc_rotate_right(x, 0x100000001ull),
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1);
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}
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