From 5a433aca1d83cfc8a270b02d89be5b3ed75a503c Mon Sep 17 00:00:00 2001 From: marxin Date: Fri, 8 Mar 2019 12:55:40 +0000 Subject: [PATCH 3/4] Backport r269492 gcc/ChangeLog: 2019-03-08 Martin Liska PR target/86952 * config/i386/i386.c (ix86_option_override_internal): Disable jump tables when retpolines are used. gcc/testsuite/ChangeLog: 2019-03-08 Martin Liska PR target/86952 * gcc.target/i386/indirect-thunk-7.c: Use jump tables to match scanned pattern. * gcc.target/i386/indirect-thunk-inline-7.c: Likewise. --- gcc/config/i386/i386.c | 6 ++++++ gcc/testsuite/gcc.target/i386/indirect-thunk-7.c | 2 +- gcc/testsuite/gcc.target/i386/indirect-thunk-inline-7.c | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index a88a29b51e6..f1de97f73df 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -4958,6 +4958,12 @@ ix86_option_override_internal (bool main_args_p, opts->x_param_values, opts_set->x_param_values); + /* PR86952: jump table usage with retpolines is slow. + The PR provides some numbers about the slowness. */ + if (ix86_indirect_branch != indirect_branch_keep + && !opts_set->x_flag_jump_tables) + opts->x_flag_jump_tables = 0; + return true; } diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-7.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-7.c index 3c72036dbaf..53868f46558 100644 --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-7.c +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-7.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */ +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic -fjump-tables" } */ void func0 (void); void func1 (void); diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-inline-7.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-inline-7.c index ea009245a58..e6f064959a1 100644 --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-inline-7.c +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-inline-7.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk-inline -fno-pic" } */ +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk-inline -fno-pic -fjump-tables" } */ void func0 (void); void func1 (void); -- 2.21.0