Hi This patch adds the no variant to -mstrict-align and the corresponding function attribute. To enable the function attribute, I have modified aarch64_can_inline_p () to allow checks even when the callee function has no attribute. The need for this is shown by the new test target_attr_18.c.
Testing: Bootstrapped, regtested and added new tests that are copies of earlier tests checking -mstrict-align with opposite scan directives. Is this ok for trunk? Sudi *** gcc/ChangeLog *** 2018-03-27 Sudakshina Das <sudi....@arm.com> * common/config/aarch64/aarch64-common.c (aarch64_handle_option): Check val before adding MASK_STRICT_ALIGN to opts->x_target_flags. * config/aarch64/aarch64.opt (mstrict-align): Remove RejectNegative. * config/aarch64/aarch64.c (aarch64_attributes): Mark allow_neg as true for strict-align. (aarch64_can_inline_p): Perform checks even when callee has no attributes to check for strict alignment. * doc/extend.texi (AArch64 Function Attributes): Document no-strict-align. * doc/invoke.texi: (AArch64 Options): Likewise. *** gcc/testsuite/ChangeLog *** 2018-03-27 Sudakshina Das <sudi....@arm.com> * gcc.target/aarch64/pr84882.c: New test. * gcc.target/aarch64/target_attr_18.c: Likewise.
diff --git a/gcc/common/config/aarch64/aarch64-common.c b/gcc/common/config/aarch64/aarch64-common.c index 7fd9305..d5655a0 100644 --- a/gcc/common/config/aarch64/aarch64-common.c +++ b/gcc/common/config/aarch64/aarch64-common.c @@ -97,7 +97,10 @@ aarch64_handle_option (struct gcc_options *opts, return true; case OPT_mstrict_align: - opts->x_target_flags |= MASK_STRICT_ALIGN; + if (val) + opts->x_target_flags |= MASK_STRICT_ALIGN; + else + opts->x_target_flags &= ~MASK_STRICT_ALIGN; return true; case OPT_momit_leaf_frame_pointer: diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index 4b5183b..4f35a6c 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -11277,7 +11277,7 @@ static const struct aarch64_attribute_info aarch64_attributes[] = { "fix-cortex-a53-843419", aarch64_attr_bool, true, NULL, OPT_mfix_cortex_a53_843419 }, { "cmodel", aarch64_attr_enum, false, NULL, OPT_mcmodel_ }, - { "strict-align", aarch64_attr_mask, false, NULL, OPT_mstrict_align }, + { "strict-align", aarch64_attr_mask, true, NULL, OPT_mstrict_align }, { "omit-leaf-frame-pointer", aarch64_attr_bool, true, NULL, OPT_momit_leaf_frame_pointer }, { "tls-dialect", aarch64_attr_enum, false, NULL, OPT_mtls_dialect_ }, @@ -11640,16 +11640,13 @@ aarch64_can_inline_p (tree caller, tree callee) tree caller_tree = DECL_FUNCTION_SPECIFIC_TARGET (caller); tree callee_tree = DECL_FUNCTION_SPECIFIC_TARGET (callee); - /* If callee has no option attributes, then it is ok to inline. */ - if (!callee_tree) - return true; - struct cl_target_option *caller_opts = TREE_TARGET_OPTION (caller_tree ? caller_tree : target_option_default_node); - struct cl_target_option *callee_opts = TREE_TARGET_OPTION (callee_tree); - + struct cl_target_option *callee_opts + = TREE_TARGET_OPTION (callee_tree ? callee_tree + : target_option_default_node); /* Callee's ISA flags should be a subset of the caller's. */ if ((caller_opts->x_aarch64_isa_flags & callee_opts->x_aarch64_isa_flags) diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt index 52eaf8c..1426b45 100644 --- a/gcc/config/aarch64/aarch64.opt +++ b/gcc/config/aarch64/aarch64.opt @@ -85,7 +85,7 @@ Target RejectNegative Joined Enum(cmodel) Var(aarch64_cmodel_var) Init(AARCH64_C Specify the code model. mstrict-align -Target Report RejectNegative Mask(STRICT_ALIGN) Save +Target Report Mask(STRICT_ALIGN) Save Don't assume that unaligned accesses are handled by the system. momit-leaf-frame-pointer diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 93a0ebc..dcda216 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -3605,8 +3605,10 @@ for the command line option @option{-mcmodel=}. @item strict-align @cindex @code{strict-align} function attribute, AArch64 Indicates that the compiler should not assume that unaligned memory references -are handled by the system. The behavior is the same as for the command-line -option @option{-mstrict-align}. +are handled by the system. To allow the compiler to assume that aligned memory +references are handled by the system, the inverse attribute +@code{no-strict-align} can be specified. The behavior is the same as for the +command-line option @option{-mstrict-align} and @option{-mno-strict-align}. @item omit-leaf-frame-pointer @cindex @code{omit-leaf-frame-pointer} function attribute, AArch64 diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index feacd56..0574d21 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -596,7 +596,7 @@ Objective-C and Objective-C++ Dialects}. @gccoptlist{-mabi=@var{name} -mbig-endian -mlittle-endian @gol -mgeneral-regs-only @gol -mcmodel=tiny -mcmodel=small -mcmodel=large @gol --mstrict-align @gol +-mstrict-align -mno-strict-align @gol -momit-leaf-frame-pointer @gol -mtls-dialect=desc -mtls-dialect=traditional @gol -mtls-size=@var{size} @gol @@ -14601,9 +14601,11 @@ Generate code for the large code model. This makes no assumptions about addresses and sizes of sections. Programs can be statically linked only. @item -mstrict-align +@itemx -mno-strict-align @opindex mstrict-align -Avoid generating memory accesses that may not be aligned on a natural object -boundary as described in the architecture specification. +@opindex mno-strict-align +Avoid or allow generating memory accesses that may not be aligned on a natural +object boundary as described in the architecture specification. @item -momit-leaf-frame-pointer @itemx -mno-omit-leaf-frame-pointer diff --git a/gcc/testsuite/gcc.target/aarch64/pr84882.c b/gcc/testsuite/gcc.target/aarch64/pr84882.c new file mode 100644 index 0000000..ffc7d55 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/pr84882.c @@ -0,0 +1,33 @@ +/* This is a copy of pr71727.c with scanning reversed. */ +/* { dg-do compile } */ +/* { dg-options "-mstrict-align -O3 -mno-strict-align" } */ + +struct test_struct_s +{ + long a; + long b; + long c; + long d; + unsigned long e; +}; + + +char _a; +struct test_struct_s xarray[128]; + +void +_start (void) +{ + struct test_struct_s *new_entry; + + new_entry = &xarray[0]; + new_entry->a = 1; + new_entry->b = 2; + new_entry->c = 3; + new_entry->d = 4; + new_entry->e = 5; + + return; +} + +/* { dg-final { scan-assembler "add\tx[0-9]+, x[0-9]+, :" {target lp64} } } */ diff --git a/gcc/testsuite/gcc.target/aarch64/target_attr_18.c b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c new file mode 100644 index 0000000..33b1d44 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c @@ -0,0 +1,21 @@ +/* This is a copy of target_attr_6.c to instead check no-strict-align. */ +/* { dg-do compile } */ +/* { dg-options "-O2 -save-temps -mstrict-align" } */ + +/* Inlining strict-align functions into non-strict align + functions is not allowed. */ + +int +bar (int a) +{ + return a - 6; +} + +__attribute__ ((target ("no-strict-align"))) +int +bam (int a) +{ + return a - bar (a); +} + +/* { dg-final { scan-assembler "bl.*bar" } } */