From 1383012ae409ed91903b2b76ee15137bc1f89900 Mon Sep 17 00:00:00 2001 From: shorne Date: Sat, 31 Aug 2019 06:00:56 +0000 Subject: [PATCH] or1k: Fix issue with set_got clobbering LR (r9) When compiling glibc we found that the GOT register was being allocated r9 when the instruction was still set_got_tmp. That is a problem because r9 is the Link Register (LR) in OpenRISC which is used/clobbered in set_got. We cannot use r9 as the GOT register. Also, we cannot simply say set_got_tmp clobbers r9 as this is the reason for having the temporary set_got_tmp. Fix by using a register class constraint that does not allow r9 during register allocation. gcc/ChangeLog: * config/or1k/constraints.md (t): New constraint. * config/or1k/or1k.h (GOT_REGS): New register class. * config/or1k/or1k.md (set_got_tmp, set_got): Use t contraint. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@275242 138bc75d-0d04-0410-961f-82ee72b054a4 (cherry picked from commit 5b9471ffca25d39635680516ba2ff85295480fc3) Signed-off-by: Romain Naour --- gcc/config/or1k/constraints.md | 4 ++++ gcc/config/or1k/or1k.h | 3 +++ gcc/config/or1k/or1k.md | 4 ++-- 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/gcc/config/or1k/constraints.md b/gcc/config/or1k/constraints.md index 93da8c058c6..a16b749008f 100644 --- a/gcc/config/or1k/constraints.md +++ b/gcc/config/or1k/constraints.md @@ -24,6 +24,7 @@ ; We use: ; c - sibcall registers +; t - got address registers (excludes LR (r9) which is clobbered by set_got) ; I - constant signed 16-bit ; K - constant unsigned 16-bit ; M - constant signed 16-bit shifted left 16-bits (l.movhi) @@ -32,6 +33,9 @@ (define_register_constraint "c" "SIBCALL_REGS" "Registers which can hold a sibling call address") +(define_register_constraint "t" "GOT_REGS" + "Registers which can be used to store the Global Offset Table (GOT) address.") + ;; Immediates (define_constraint "I" "A signed 16-bit immediate in the range -32768 to 32767." diff --git a/gcc/config/or1k/or1k.h b/gcc/config/or1k/or1k.h index 6dda230f217..feee702d89c 100644 --- a/gcc/config/or1k/or1k.h +++ b/gcc/config/or1k/or1k.h @@ -189,6 +189,7 @@ enum reg_class { NO_REGS, SIBCALL_REGS, + GOT_REGS, GENERAL_REGS, FLAG_REGS, ALL_REGS, @@ -200,6 +201,7 @@ enum reg_class #define REG_CLASS_NAMES { \ "NO_REGS", \ "SIBCALL_REGS", \ + "GOT_REGS", \ "GENERAL_REGS", \ "FLAG_REGS", \ "ALL_REGS" } @@ -212,6 +214,7 @@ enum reg_class #define REG_CLASS_CONTENTS \ { { 0x00000000, 0x00000000 }, \ { SIBCALL_REGS_MASK, 0 }, \ + { 0xfffffdff, 0x00000000 }, \ { 0xffffffff, 0x00000003 }, \ { 0x00000000, 0x00000004 }, \ { 0xffffffff, 0x00000007 } \ diff --git a/gcc/config/or1k/or1k.md b/gcc/config/or1k/or1k.md index 2dad51cd46b..88f3f02630f 100644 --- a/gcc/config/or1k/or1k.md +++ b/gcc/config/or1k/or1k.md @@ -595,7 +595,7 @@ ;; set_got pattern below. This works because the set_got_tmp insn is the ;; first insn in the stream and that it isn't moved during RA. (define_insn "set_got_tmp" - [(set (match_operand:SI 0 "register_operand" "=r") + [(set (match_operand:SI 0 "register_operand" "=t") (unspec_volatile:SI [(const_int 0)] UNSPECV_SET_GOT))] "" { @@ -604,7 +604,7 @@ ;; The insn to initialize the GOT. (define_insn "set_got" - [(set (match_operand:SI 0 "register_operand" "=r") + [(set (match_operand:SI 0 "register_operand" "=t") (unspec:SI [(const_int 0)] UNSPEC_SET_GOT)) (clobber (reg:SI LR_REGNUM))] "" -- 2.24.1