The following patch fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87246
The patch was successfully bootstrapped and tested on x86-64 and ppc64. Committed as rev. 268404
Index: ChangeLog =================================================================== --- ChangeLog (revision 268403) +++ ChangeLog (working copy) @@ -1,3 +1,9 @@ +2019-01-30 Vladimir Makarov <vmaka...@redhat.com> + + PR rtl-optimization/87246 + * lra-constraints.c (simplify_operand_subreg): Reload memory + in subreg if the address became invalid. + 2019-01-30 Bill Schmidt <wschm...@linux.ibm.com> PR target/87064 Index: lra-constraints.c =================================================================== --- lra-constraints.c (revision 268117) +++ lra-constraints.c (working copy) @@ -1497,10 +1497,11 @@ simplify_operand_subreg (int nop, machin alter_subreg (curr_id->operand_loc[nop], false); rtx subst = *curr_id->operand_loc[nop]; lra_assert (MEM_P (subst)); - + const bool addr_is_valid = valid_address_p (GET_MODE (subst), + XEXP (subst, 0), + MEM_ADDR_SPACE (subst)); if (!addr_was_valid - || valid_address_p (GET_MODE (subst), XEXP (subst, 0), - MEM_ADDR_SPACE (subst)) + || addr_is_valid || ((get_constraint_type (lookup_constraint (curr_static_id->operand[nop].constraint)) != CT_SPECIAL_MEMORY) @@ -1529,12 +1530,17 @@ simplify_operand_subreg (int nop, machin data into a register when the inner is narrower than outer or missing important data from memory when the inner is wider than outer. This rule only applies to modes that are no wider than - a word. */ - if (!(maybe_ne (GET_MODE_PRECISION (mode), - GET_MODE_PRECISION (innermode)) - && known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD) - && known_le (GET_MODE_SIZE (innermode), UNITS_PER_WORD) - && WORD_REGISTER_OPERATIONS) + a word. + + If valid memory becomes invalid after subreg elimination + we still have to reload memory. + */ + if ((! addr_was_valid || addr_is_valid) + && !(maybe_ne (GET_MODE_PRECISION (mode), + GET_MODE_PRECISION (innermode)) + && known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD) + && known_le (GET_MODE_SIZE (innermode), UNITS_PER_WORD) + && WORD_REGISTER_OPERATIONS) && (!(MEM_ALIGN (subst) < GET_MODE_ALIGNMENT (mode) && targetm.slow_unaligned_access (mode, MEM_ALIGN (subst))) || (MEM_ALIGN (reg) < GET_MODE_ALIGNMENT (innermode) @@ -1553,7 +1559,7 @@ simplify_operand_subreg (int nop, machin enum reg_class rclass = (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS); if (get_reload_reg (curr_static_id->operand[nop].type, innermode, - reg, rclass, TRUE, "slow mem", &new_reg)) + reg, rclass, TRUE, "slow/invalid mem", &new_reg)) { bool insert_before, insert_after; bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg)); @@ -1572,7 +1578,7 @@ simplify_operand_subreg (int nop, machin rclass = (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS); if (get_reload_reg (curr_static_id->operand[nop].type, mode, reg, - rclass, TRUE, "slow mem", &new_reg)) + rclass, TRUE, "slow/invalid mem", &new_reg)) { bool insert_before, insert_after; bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg)); @@ -1585,7 +1591,7 @@ simplify_operand_subreg (int nop, machin } *curr_id->operand_loc[nop] = new_reg; lra_process_new_insns (curr_insn, before, after, - "Inserting slow mem reload"); + "Inserting slow/invalid mem reload"); return true; } Index: testsuite/ChangeLog =================================================================== --- testsuite/ChangeLog (revision 268403) +++ testsuite/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2019-01-30 Vladimir Makarov <vmaka...@redhat.com> + + PR rtl-optimization/87246 + * gcc.target/i386/pr87246.c: New. + 2019-01-30 Marek Polacek <pola...@redhat.com> PR c++/89119 - ICE with value-initialization in template. @@ -15,7 +20,7 @@ * gcc.target/powerpc/vec-extract-uint128-1.c: New test. * gcc.target/powerpc/vec-extract-ulong-1.c: New test. * gcc.target/powerpc/vec-extract-ushort-1.c: New test. - + 2019-01-30 Richard Biener <rguent...@suse.de> PR tree-optimization/89111 Index: testsuite/gcc.target/i386/pr87246.c =================================================================== --- testsuite/gcc.target/i386/pr87246.c (nonexistent) +++ testsuite/gcc.target/i386/pr87246.c (working copy) @@ -0,0 +1,22 @@ +/* PR rtl-optimization/87246 */ +/* { dg-do compile { target int128 } } */ +/* { dg-options "-O2 -w -fnon-call-exceptions -fno-split-wide-types" } */ + +__int128 zd; +int c1; + +void +s2 (__int128 *qv) +{ + if (*qv != 0) + { + zd = 0; + c1 = c1 <= *qv; + } +} + +void +lt (unsigned int vb) +{ + s2 (vb + 1); +}