[PATCH] D41060: Add an option for ICFing data
Rafael Ávila de Espíndola via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon Dec 11 14:34:17 PST 2017
rafael updated this revision to Diff 126450.
rafael added a comment.
Rebased and updated description.
https://reviews.llvm.org/D41060
Files:
ELF/Config.h
ELF/Driver.cpp
ELF/ICF.cpp
ELF/Options.td
test/ELF/icf9.s
Index: test/ELF/icf9.s
===================================================================
--- test/ELF/icf9.s
+++ test/ELF/icf9.s
@@ -10,14 +10,23 @@
# CHECK-NOT: selected .rodata.d1
# CHECK-NOT: selected .rodata.d2
+# We do merge rodata if passed --icf-data
+# RUN: ld.lld %t -o %t2 --icf=all --verbose --icf-data 2>&1 | FileCheck --check-prefix=DATA %s
+# RUN: llvm-readelf -S -W %t2 | FileCheck --check-prefix=DATA-SEC %s
+
+# DATA: selected .rodata.d1
+# DATA: removed .rodata.d2
+
+# DATA-SEC: .rodata PROGBITS 0000000000200120 000120 000001 00 A 0 0 1
+
.globl _start, d1, d2
_start:
ret
-.section .rodata.f1, "a"
+.section .rodata.d1, "a"
d1:
.byte 1
-.section .rodata.f2, "a"
+.section .rodata.d2, "a"
d2:
.byte 1
Index: ELF/Options.td
===================================================================
--- ELF/Options.td
+++ ELF/Options.td
@@ -143,6 +143,9 @@
def icf_all: F<"icf=all">, HelpText<"Enable identical code folding">;
+def icf_data: F<"icf-data">,
+ HelpText<"Enable ICF to also fold identical read only data">;
+
def icf_none: F<"icf=none">, HelpText<"Disable identical code folding">;
defm image_base : Eq<"image-base">, HelpText<"Set the base address">;
Index: ELF/ICF.cpp
===================================================================
--- ELF/ICF.cpp
+++ ELF/ICF.cpp
@@ -161,11 +161,15 @@
// Returns true if section S is subject of ICF.
static bool isEligible(InputSection *S) {
+ // Don't merge read only data sections unless --icf-data was passed.
+ if (!(S->Flags & SHF_EXECINSTR) && !Config->ICFData)
+ return false;
+
// .init and .fini contains instructions that must be executed to
// initialize and finalize the process. They cannot and should not
// be merged.
- return S->Live && (S->Flags & SHF_ALLOC) && (S->Flags & SHF_EXECINSTR) &&
- !(S->Flags & SHF_WRITE) && S->Name != ".init" && S->Name != ".fini";
+ return S->Live && (S->Flags & SHF_ALLOC) && !(S->Flags & SHF_WRITE) &&
+ S->Name != ".init" && S->Name != ".fini";
}
// Split an equivalence class into smaller classes.
Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -618,6 +618,7 @@
Config->GcSections = Args.hasFlag(OPT_gc_sections, OPT_no_gc_sections, false);
Config->GdbIndex = Args.hasFlag(OPT_gdb_index, OPT_no_gdb_index, false);
Config->ICF = Args.hasFlag(OPT_icf_all, OPT_icf_none, false);
+ Config->ICFData = Args.hasArg(OPT_icf_data);
Config->Init = Args.getLastArgValue(OPT_init, "_init");
Config->LTOAAPipeline = Args.getLastArgValue(OPT_lto_aa_pipeline);
Config->LTONewPmPasses = Args.getLastArgValue(OPT_lto_newpm_passes);
Index: ELF/Config.h
===================================================================
--- ELF/Config.h
+++ ELF/Config.h
@@ -126,6 +126,7 @@
bool HasDynamicList = false;
bool HasDynSymTab;
bool ICF;
+ bool ICFData;
bool MipsN32Abi = false;
bool NoGnuUnique;
bool NoUndefinedVersion;
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D41060.126450.patch
Type: text/x-patch
Size: 3021 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20171211/fbd9e710/attachment.bin>
More information about the llvm-commits
mailing list