Implement PowerPC64 .localentry for value 1
Alan Modra
amodra@gmail.com
Thu Jul 26 07:52:00 GMT 2018
This adds support for ".localentry 1", a new st_other
STO_PPC64_LOCAL_MASK encoding that signifies a function with a single
entry point like ".localentry 0", but unlike a ".localentry 0"
function does not preserve r2.
include/
* elf/ppc64.h: Specify byte offset to local entry for values
of two to six in STO_PPC64_LOCAL_MASK. Clarify r2 return
value for such functions when entering via global entry point.
Specify meaning of a value of one in STO_PPC64_LOCAL_MASK.
bfd/
* elf64-ppc.c (ppc64_elf_size_stubs): Use a ppc_stub_long_branch_r2off
for calls to symbols with STO_PPC64_LOCAL_MASK bits set to 1.
gas/
* config/tc-ppc.c (ppc_elf_localentry): Allow .localentry values
of 1 and 7 to directly set value into STO_PPC64_LOCAL_MASK bits.
ld/testsuite/
* ld-powerpc/elfv2.s: Add .localentry f5,1 testcase.
* ld-powerpc/elfv2exe.d: Update.
* ld-powerpc/elfv2so.d: Update.
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 6b293ce5fd..5cd3b8dde3 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -12862,12 +12862,15 @@ ppc64_elf_size_stubs (struct bfd_link_info *info)
_init and _fini functions, it may be that a
call to what looks like a local sym is in
fact a call needing a TOC adjustment. */
- if (code_sec != NULL
- && code_sec->output_section != NULL
- && (htab->sec_info[code_sec->id].toc_off
- != htab->sec_info[section->id].toc_off)
- && (code_sec->has_toc_reloc
- || code_sec->makes_toc_func_call))
+ if ((code_sec != NULL
+ && code_sec->output_section != NULL
+ && (htab->sec_info[code_sec->id].toc_off
+ != htab->sec_info[section->id].toc_off)
+ && (code_sec->has_toc_reloc
+ || code_sec->makes_toc_func_call))
+ || (((hash ? hash->elf.other : sym->st_other)
+ & STO_PPC64_LOCAL_MASK)
+ == 1 << STO_PPC64_LOCAL_BIT))
stub_type = ppc_stub_long_branch_r2off;
}
diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 92e5eb5d39..4388b2570b 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -2378,12 +2378,22 @@ ppc_elf_localentry (int ignore ATTRIBUTE_UNUSED)
if (resolve_expression (&exp)
&& exp.X_op == O_constant)
{
- unsigned char encoded = PPC64_SET_LOCAL_ENTRY_OFFSET (exp.X_add_number);
+ unsigned int encoded, ok;
- if (exp.X_add_number != (offsetT) PPC64_LOCAL_ENTRY_OFFSET (encoded))
- as_bad (_(".localentry expression for `%s' "
- "is not a valid power of 2"), S_GET_NAME (sym));
+ ok = 1;
+ if (exp.X_add_number == 1 || exp.X_add_number == 7)
+ encoded = exp.X_add_number << STO_PPC64_LOCAL_BIT;
else
+ {
+ encoded = PPC64_SET_LOCAL_ENTRY_OFFSET (exp.X_add_number);
+ if (exp.X_add_number != (offsetT) PPC64_LOCAL_ENTRY_OFFSET (encoded))
+ {
+ as_bad (_(".localentry expression for `%s' "
+ "is not a valid power of 2"), S_GET_NAME (sym));
+ ok = 0;
+ }
+ }
+ if (ok)
{
bfdsym = symbol_get_bfdsym (sym);
elfsym = elf_symbol_from (bfd_asymbol_bfd (bfdsym), bfdsym);
diff --git a/include/elf/ppc64.h b/include/elf/ppc64.h
index 501aebc1be..387c1d6404 100644
--- a/include/elf/ppc64.h
+++ b/include/elf/ppc64.h
@@ -198,13 +198,15 @@ END_RELOC_NUMBERS (R_PPC64_max)
#define EF_PPC64_ABI 3
/* The ELFv2 ABI uses three bits in the symbol st_other field of a
- function definition to specify the number of instructions between a
+ function definition to specify the number of bytes between a
function's global entry point and local entry point.
+ Values of two to six specify powers of two from four to sixty four
+ bytes. For such functions:
The global entry point is used when it is necessary to set up the
toc pointer (r2) for the function. Callers must enter the global
entry point with r12 set to the global entry point address. On
- return from the function, r2 may have a different value to that
- which it had on entry.
+ return from the function r2 will contain the toc pointer for the
+ function.
The local entry point is used when r2 is known to already be valid
for the function. There is no requirement on r12 when using the
local entry point, and on return r2 will contain the same value as
@@ -212,7 +214,9 @@ END_RELOC_NUMBERS (R_PPC64_max)
A value of zero in these bits means that the function has a single
entry point with no requirement on r12 or r2, and that on return r2
will contain the same value as at entry.
- Values of one and seven are reserved. */
+ A value of one means that the function has a single entry point
+ with no requirement on r12 or r2, and that r2 is *not* preserved.
+ A value of seven is reserved. */
#define STO_PPC64_LOCAL_BIT 5
#define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT)
diff --git a/ld/testsuite/ld-powerpc/elfv2.s b/ld/testsuite/ld-powerpc/elfv2.s
index c2a4c3bf86..4fedbb7c52 100644
--- a/ld/testsuite/ld-powerpc/elfv2.s
+++ b/ld/testsuite/ld-powerpc/elfv2.s
@@ -25,8 +25,17 @@ f1:
nop
bl f4
nop
+ bl f5
+ nop
ld 0,48(1)
addi 1,1,32
mtlr 0
blr
.size f1,.-f1
+
+ .globl f5
+ .type f5,@function
+f5:
+ .localentry f5,1
+ blr
+ .size f5,.-f5
diff --git a/ld/testsuite/ld-powerpc/elfv2exe.d b/ld/testsuite/ld-powerpc/elfv2exe.d
index 77bf6e2568..d08e600aa4 100644
--- a/ld/testsuite/ld-powerpc/elfv2exe.d
+++ b/ld/testsuite/ld-powerpc/elfv2exe.d
@@ -9,17 +9,22 @@ Disassembly of section \.text:
0+100000c0 <.*\.plt_branch\.f4>:
.*: (3d 82 ff ff|ff ff 82 3d) addis r12,r2,-1
-.*: (e9 8c 7f 28|28 7f 8c e9) ld r12,32552\(r12\)
+.*: (e9 8c 7f 58|58 7f 8c e9) ld r12,32600\(r12\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
0+100000d0 <.*\.plt_branch\.f2>:
.*: (3d 82 ff ff|ff ff 82 3d) addis r12,r2,-1
-.*: (e9 8c 7f 30|30 7f 8c e9) ld r12,32560\(r12\)
+.*: (e9 8c 7f 60|60 7f 8c e9) ld r12,32608\(r12\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
-0+100000e0 <(f1|_start)>:
+0+100000e0 <.*\.long_branch_r2off\.f5>:
+.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
+.*: (48 00 00 6c|6c 00 00 48) b .* <f5>
+ \.\.\.
+
+0+10000100 <(f1|_start)>:
.*: (3c 40 10 02|02 10 40 3c) lis r2,4098
.*: (38 42 82 00|00 82 42 38) addi r2,r2,-32256
.*: (7c 08 02 a6|a6 02 08 7c) mflr r0
@@ -27,14 +32,19 @@ Disassembly of section \.text:
.*: (f8 01 00 30|30 00 01 f8) std r0,48\(r1\)
.*: (4b ff ff f5|f5 ff ff 4b) bl .* <(f1|_start)\+0x8>
.*: (e8 62 80 08|08 80 62 e8) ld r3,-32760\(r2\)
-.*: (4b ff ff d5|d5 ff ff 4b) bl .*\.plt_branch\.f2>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_branch\.f2>
.*: (60 00 00 00|00 00 00 60) nop
.*: (e8 62 80 10|10 80 62 e8) ld r3,-32752\(r2\)
-.*: (48 00 87 81|81 87 00 48) bl 10008888 <f3>
+.*: (48 .. .. ..|.. .. .. 48) bl 10008888 <f3>
.*: (60 00 00 00|00 00 00 60) nop
-.*: (4b ff ff b1|b1 ff ff 4b) bl .*\.plt_branch\.f4>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_branch\.f4>
.*: (60 00 00 00|00 00 00 60) nop
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.long_branch_r2off\.f5>
+.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
.*: (e8 01 00 30|30 00 01 e8) ld r0,48\(r1\)
.*: (38 21 00 20|20 00 21 38) addi r1,r1,32
.*: (7c 08 03 a6|a6 03 08 7c) mtlr r0
.*: (4e 80 00 20|20 00 80 4e) blr
+
+0+10000150 <f5>:
+.*: (4e 80 00 20|20 00 80 4e) blr
diff --git a/ld/testsuite/ld-powerpc/elfv2so.d b/ld/testsuite/ld-powerpc/elfv2so.d
index 5f198a9691..0853f8abb3 100644
--- a/ld/testsuite/ld-powerpc/elfv2so.d
+++ b/ld/testsuite/ld-powerpc/elfv2so.d
@@ -9,13 +9,20 @@ Disassembly of section \.text:
.* <.*\.plt_call\.f4>:
.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
-.*: (e9 82 80 38|38 80 82 e9) ld r12,-32712\(r2\)
+.*: (e9 82 80 40|40 80 82 e9) ld r12,-32704\(r2\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
\.\.\.
.* <.*\.plt_call\.f3>:
.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
+.*: (e9 82 80 30|30 80 82 e9) ld r12,-32720\(r2\)
+.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
+.*: (4e 80 04 20|20 04 80 4e) bctr
+ \.\.\.
+
+.* <.*\.plt_call\.f5>:
+.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
.*: (e9 82 80 28|28 80 82 e9) ld r12,-32728\(r2\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
@@ -23,14 +30,14 @@ Disassembly of section \.text:
.* <.*\.plt_call\.f1>:
.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
-.*: (e9 82 80 40|40 80 82 e9) ld r12,-32704\(r2\)
+.*: (e9 82 80 48|48 80 82 e9) ld r12,-32696\(r2\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
\.\.\.
.* <.*\.plt_call\.f2>:
.*: (f8 41 00 18|18 00 41 f8) std r2,24\(r1\)
-.*: (e9 82 80 30|30 80 82 e9) ld r12,-32720\(r2\)
+.*: (e9 82 80 38|38 80 82 e9) ld r12,-32712\(r2\)
.*: (7d 89 03 a6|a6 03 89 7d) mtctr r12
.*: (4e 80 04 20|20 04 80 4e) bctr
\.\.\.
@@ -41,19 +48,25 @@ Disassembly of section \.text:
.*: (7c 08 02 a6|a6 02 08 7c) mflr r0
.*: (f8 21 ff e1|e1 ff 21 f8) stdu r1,-32\(r1\)
.*: (f8 01 00 30|30 00 01 f8) std r0,48\(r1\)
-.*: (4b ff ff ad|ad ff ff 4b) bl .*\.plt_call\.f1>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_call\.f1>
.*: (e8 62 80 08|08 80 62 e8) ld r3,-32760\(r2\)
-.*: (4b ff ff c5|c5 ff ff 4b) bl .*\.plt_call\.f2>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_call\.f2>
.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
.*: (e8 62 80 10|10 80 62 e8) ld r3,-32752\(r2\)
-.*: (4b ff ff 79|79 ff ff 4b) bl .*\.plt_call\.f3>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_call\.f3>
+.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_call\.f4>
.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
-.*: (4b ff ff 51|51 ff ff 4b) bl .*\.plt_call\.f4>
+.*: (4b .. .. ..|.. .. .. 4b) bl .*\.plt_call\.f5>
.*: (e8 41 00 18|18 00 41 e8) ld r2,24\(r1\)
.*: (e8 01 00 30|30 00 01 e8) ld r0,48\(r1\)
.*: (38 21 00 20|20 00 21 38) addi r1,r1,32
.*: (7c 08 03 a6|a6 03 08 7c) mtlr r0
.*: (4e 80 00 20|20 00 80 4e) blr
+
+.* <f5>:
+.*: (4e 80 00 20|20 00 80 4e) blr
+.*: (60 00 00 00|00 00 00 60) nop
.*
.*
@@ -73,14 +86,17 @@ Disassembly of section \.text:
.*: (e9 6b 00 08|08 00 6b e9) ld r11,8\(r11\)
.*: (4e 80 04 20|20 04 80 4e) bctr
-.* <f3@plt>:
+.* <f5@plt>:
.*: (4b ff ff c8|c8 ff ff 4b) b .* <__glink_PLTresolve>
-.* <f2@plt>:
+.* <f3@plt>:
.*: (4b ff ff c4|c4 ff ff 4b) b .* <__glink_PLTresolve>
-.* <f4@plt>:
+.* <f2@plt>:
.*: (4b ff ff c0|c0 ff ff 4b) b .* <__glink_PLTresolve>
-.* <f1@plt>:
+.* <f4@plt>:
.*: (4b ff ff bc|bc ff ff 4b) b .* <__glink_PLTresolve>
+
+.* <f1@plt>:
+.*: (4b ff ff b8|b8 ff ff 4b) b .* <__glink_PLTresolve>
--
Alan Modra
Australia Development Lab, IBM
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