From 3703b60c903e1cb7629c1a51cda68e53ebd8fbe8 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Mon, 22 Oct 2018 08:21:03 +0000 Subject: [PATCH] S/390: Make "b" constraint match literal pool references Improves the code generation by getting rid of redundant LAs, as seen in the following example: - la %r1,0(%r13) - lg %r4,0(%r1) + lg %r4,0(%r13) Also allows to proceed with the merge of movdi_64 and movdi_larl. Currently LRA decides to spill literal pool references back to the literal pool, because it preliminarily chooses alternatives with CT_MEMORY constraints without calling satisfies_memory_constraint_p (). Later on it notices that the constraint is wrong and fixes it by spilling. The constraint in this case is "b", and the operand is a literal pool reference. There is no reason to reject them. The current behavior was introduced, apparently unintentionally, by https://gcc.gnu.org/ml/gcc-patches/2010-09/msg00812.html The patch affects a little bit more than mentioned in the subject, because it changes s390_loadrelative_operand_p (), which is called not only for checking the "b" constraint. However, the only caller for which it should really not accept literal pool references is s390_check_qrst_address (), so it was changed to explicitly do so. gcc/ChangeLog: 2018-10-22 Ilya Leoshkevich * config/s390/s390.c (s390_loadrelative_operand_p): Accept literal pool references. (s390_check_qrst_address): Adapt to the new behavior of s390_loadrelative_operand_p (). gcc/testsuite/ChangeLog: 2018-10-22 Ilya Leoshkevich * gcc.target/s390/litpool-int.c: New test. From-SVN: r265371 --- gcc/ChangeLog | 7 +++++++ gcc/config/s390/s390.c | 9 +++++---- gcc/testsuite/ChangeLog | 4 ++++ 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7b1a98b8fb4..fe4898c1cb6 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2018-10-22 Ilya Leoshkevich + + * config/s390/s390.c (s390_loadrelative_operand_p): Accept + literal pool references. + (s390_check_qrst_address): Adapt to the new behavior of + s390_loadrelative_operand_p (). + 2018-10-22 H.J. Lu PR target/72782 diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c index ab22c2c8be5..1de1a716aa3 100644 --- a/gcc/config/s390/s390.c +++ b/gcc/config/s390/s390.c @@ -3110,8 +3110,7 @@ s390_legitimate_address_without_index_p (rtx op) Valid addresses are single references or a sum of a reference and a constant integer. Return these parts in SYMREF and ADDEND. You can pass NULL in REF and/or ADDEND if you are not interested in these - values. Literal pool references are *not* considered symbol - references. */ + values. */ static bool s390_loadrelative_operand_p (rtx addr, rtx *symref, HOST_WIDE_INT *addend) @@ -3130,7 +3129,7 @@ s390_loadrelative_operand_p (rtx addr, rtx *symref, HOST_WIDE_INT *addend) addr = XEXP (addr, 0); } - if ((GET_CODE (addr) == SYMBOL_REF && !CONSTANT_POOL_ADDRESS_P (addr)) + if (GET_CODE (addr) == SYMBOL_REF || (GET_CODE (addr) == UNSPEC && (XINT (addr, 1) == UNSPEC_GOTENT || XINT (addr, 1) == UNSPEC_PLT))) @@ -3153,6 +3152,7 @@ s390_loadrelative_operand_p (rtx addr, rtx *symref, HOST_WIDE_INT *addend) static int s390_check_qrst_address (char c, rtx op, bool lit_pool_ok) { + rtx symref; struct s390_address addr; bool decomposed = false; @@ -3161,7 +3161,8 @@ s390_check_qrst_address (char c, rtx op, bool lit_pool_ok) /* This check makes sure that no symbolic address (except literal pool references) are accepted by the R or T constraints. */ - if (s390_loadrelative_operand_p (op, NULL, NULL)) + if (s390_loadrelative_operand_p (op, &symref, NULL) + && (!lit_pool_ok || !CONSTANT_POOL_ADDRESS_P (symref))) return 0; /* Ensure literal pool references are only accepted if LIT_POOL_OK. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 27d1ab98718..bb22d82864d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2018-10-22 Ilya Leoshkevich + + * gcc.target/s390/litpool-int.c: New test. + 2018-10-22 H.J. Lu PR target/72782 -- 2.30.2