Hi! The task of the build_bitint_stmt_ssa_conflicts hook for tree-ssa-coalesce.cc next to special casing the multiplication/division/modulo is to ignore statements with large/huge _BitInt lhs which isn't in names bitmap and on the other side pretend all uses of the stmt are used in a later stmt (single user of that SSA_NAME or perhaps single user of lhs of the single user etc.) where the lowering will actually emit the code.
Unfortunately the function wasn't handling COMPLEX_TYPE of the large/huge BITINT_TYPE, while the FE doesn't really support such types, they are used under the hood for __builtin_{add,sub,mul}_overflow{,_p}, they are also present or absent from the names bitmap and should be treated the same. Without this patch, the operands of .ADD_OVERFLOW were incorrectly pretended to be used right in that call statement rather than on the cast stmt from IMAGPART_EXPR of .ADD_OVERFLOW return value to some integral type. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2024-03-23 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/114425 * gimple-lower-bitint.cc (build_bitint_stmt_ssa_conflicts): Handle _Complex large/huge _BitInt types like the large/huge _BitInt types. * gcc.dg/torture/bitint-67.c: New test. --- gcc/gimple-lower-bitint.cc.jj 2024-03-22 09:21:28.350087044 +0100 +++ gcc/gimple-lower-bitint.cc 2024-03-22 14:54:41.767972684 +0100 @@ -5902,20 +5902,25 @@ build_bitint_stmt_ssa_conflicts (gimple if (is_gimple_assign (stmt)) { lhs = gimple_assign_lhs (stmt); - if (TREE_CODE (lhs) == SSA_NAME - && TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE - && bitint_precision_kind (TREE_TYPE (lhs)) >= bitint_prec_large) + if (TREE_CODE (lhs) == SSA_NAME) { - if (!bitmap_bit_p (names, SSA_NAME_VERSION (lhs))) - return; - switch (gimple_assign_rhs_code (stmt)) + tree type = TREE_TYPE (lhs); + if (TREE_CODE (type) == COMPLEX_TYPE) + type = TREE_TYPE (type); + if (TREE_CODE (type) == BITINT_TYPE + && bitint_precision_kind (type) >= bitint_prec_large) { - case MULT_EXPR: - case TRUNC_DIV_EXPR: - case TRUNC_MOD_EXPR: - muldiv_p = true; - default: - break; + if (!bitmap_bit_p (names, SSA_NAME_VERSION (lhs))) + return; + switch (gimple_assign_rhs_code (stmt)) + { + case MULT_EXPR: + case TRUNC_DIV_EXPR: + case TRUNC_MOD_EXPR: + muldiv_p = true; + default: + break; + } } } } @@ -5947,27 +5952,37 @@ build_bitint_stmt_ssa_conflicts (gimple auto_vec<tree, 16> worklist; FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE) - if (TREE_CODE (TREE_TYPE (var)) == BITINT_TYPE - && bitint_precision_kind (TREE_TYPE (var)) >= bitint_prec_large) - { - if (bitmap_bit_p (names, SSA_NAME_VERSION (var))) - use (live, var); - else - worklist.safe_push (var); - } + { + tree type = TREE_TYPE (var); + if (TREE_CODE (type) == COMPLEX_TYPE) + type = TREE_TYPE (type); + if (TREE_CODE (type) == BITINT_TYPE + && bitint_precision_kind (type) >= bitint_prec_large) + { + if (bitmap_bit_p (names, SSA_NAME_VERSION (var))) + use (live, var); + else + worklist.safe_push (var); + } + } while (worklist.length () > 0) { tree s = worklist.pop (); FOR_EACH_SSA_TREE_OPERAND (var, SSA_NAME_DEF_STMT (s), iter, SSA_OP_USE) - if (TREE_CODE (TREE_TYPE (var)) == BITINT_TYPE - && bitint_precision_kind (TREE_TYPE (var)) >= bitint_prec_large) - { - if (bitmap_bit_p (names, SSA_NAME_VERSION (var))) - use (live, var); - else - worklist.safe_push (var); - } + { + tree type = TREE_TYPE (var); + if (TREE_CODE (type) == COMPLEX_TYPE) + type = TREE_TYPE (type); + if (TREE_CODE (type) == BITINT_TYPE + && bitint_precision_kind (type) >= bitint_prec_large) + { + if (bitmap_bit_p (names, SSA_NAME_VERSION (var))) + use (live, var); + else + worklist.safe_push (var); + } + } } if (muldiv_p) --- gcc/testsuite/gcc.dg/torture/bitint-67.c.jj 2024-03-22 14:53:52.929642342 +0100 +++ gcc/testsuite/gcc.dg/torture/bitint-67.c 2024-03-22 14:54:29.205144953 +0100 @@ -0,0 +1,29 @@ +/* PR tree-optimization/114425 */ +/* { dg-do run { target bitint } } */ +/* { dg-options "-std=c23" } */ +/* { dg-skip-if "" { ! run_expensive_tests } { "*" } { "-O0" "-O2" } } */ +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */ + +#if __BITINT_MAXWIDTH__ >= 2000 +_BitInt(8) a; +_BitInt(300) b; +_BitInt(2000) c; + +__attribute__((noipa)) unsigned +foo (_BitInt(2000) d) +{ + int o = __builtin_add_overflow_p (d, 0, b); + _BitInt(2000) m = c * a; + unsigned u = m; + return u + o; +} +#endif + +int +main () +{ +#if __BITINT_MAXWIDTH__ >= 2000 + if (foo (0xfa7ac16f2613255eeb217e871c1f02221e26ce11f82d6a33206ec0ad5d4414722019933c0e2wb) != 1) + __builtin_abort (); +#endif +} Jakub