Don't touch r11 in __tls_get_addr stub

Message ID 20200120095444.GF4433@bubble.grove.modra.org
State New
Headers show
Series
  • Don't touch r11 in __tls_get_addr stub
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Commit Message

Alan Modra Jan. 20, 2020, 9:54 a.m.
This modifies the special __tls_get_addr stub that checks for a
tlsdesc style __tls_index entry and returns early.  Not using r11
isn't much benefit at the moment but a followup patch will preserve
regs around the first call to __tls_get_addr when the __tls_index
entry isn't yet set up for an early return.

bfd/
	* elf64-ppc.c (LD_R11_0R3, CMPDI_R11_0, STD_R11_0R1, LD_R11_0R1),
	(MTLR_R11): Don't define.
	(LD_R0_0R3, CMPDI_R0_0): Define.
	(build_tls_get_addr_stub): Don't use r11 in stub.
ld/
	* testsuite/ld-powerpc/tlsexe.d: Match new __tls_get_addr stub.
	* testsuite/ld-powerpc/tlsexeno.d: Likewise.
	* testsuite/ld-powerpc/tlsexetoc.d: Likewise.
	* testsuite/ld-powerpc/tlsexetocno.d: Likewise.
	* testsuite/ld-powerpc/tlsopt5.d: Likewise.


-- 
Alan Modra
Australia Development Lab, IBM

Patch

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 0e906cb481..3ae294b500 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -10885,17 +10885,14 @@  build_plt_stub (struct ppc_link_hash_table *htab,
 
 /* Build a special .plt call stub for __tls_get_addr.  */
 
-#define LD_R11_0R3	0xe9630000
+#define LD_R0_0R3	0xe8030000
 #define LD_R12_0R3	0xe9830000
 #define MR_R0_R3	0x7c601b78
-#define CMPDI_R11_0	0x2c2b0000
+#define CMPDI_R0_0	0x2c200000
 #define ADD_R3_R12_R13	0x7c6c6a14
 #define BEQLR		0x4d820020
 #define MR_R3_R0	0x7c030378
-#define STD_R11_0R1	0xf9610000
 #define BCTRL		0x4e800421
-#define LD_R11_0R1	0xe9610000
-#define MTLR_R11	0x7d6803a6
 
 static inline bfd_byte *
 build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
@@ -10905,10 +10902,10 @@  build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
   bfd *obfd = htab->params->stub_bfd;
   bfd_byte *loc = p;
 
-  bfd_put_32 (obfd, LD_R11_0R3 + 0, p),		p += 4;
+  bfd_put_32 (obfd, LD_R0_0R3 + 0, p),		p += 4;
   bfd_put_32 (obfd, LD_R12_0R3 + 8, p),		p += 4;
+  bfd_put_32 (obfd, CMPDI_R0_0, p),		p += 4;
   bfd_put_32 (obfd, MR_R0_R3, p),		p += 4;
-  bfd_put_32 (obfd, CMPDI_R11_0, p),		p += 4;
   bfd_put_32 (obfd, ADD_R3_R12_R13, p),		p += 4;
   bfd_put_32 (obfd, BEQLR, p),			p += 4;
   bfd_put_32 (obfd, MR_R3_R0, p),		p += 4;
@@ -10917,8 +10914,8 @@  build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
   if (stub_entry->stub_type != ppc_stub_plt_call_r2save)
     return build_plt_stub (htab, stub_entry, p, offset, r);
 
-  bfd_put_32 (obfd, MFLR_R11, p),		p += 4;
-  bfd_put_32 (obfd, STD_R11_0R1 + STK_LINKER (htab), p), p += 4;
+  bfd_put_32 (obfd, MFLR_R0, p),		p += 4;
+  bfd_put_32 (obfd, STD_R0_0R1 + STK_LINKER (htab), p), p += 4;
 
   if (r != NULL)
     r[0].r_offset += 2 * 4;
@@ -10926,8 +10923,8 @@  build_tls_get_addr_stub (struct ppc_link_hash_table *htab,
   bfd_put_32 (obfd, BCTRL, p - 4);
 
   bfd_put_32 (obfd, LD_R2_0R1 + STK_TOC (htab), p),	p += 4;
-  bfd_put_32 (obfd, LD_R11_0R1 + STK_LINKER (htab), p),	p += 4;
-  bfd_put_32 (obfd, MTLR_R11, p),		p += 4;
+  bfd_put_32 (obfd, LD_R0_0R1 + STK_LINKER (htab), p),	p += 4;
+  bfd_put_32 (obfd, MTLR_R0, p),		p += 4;
   bfd_put_32 (obfd, BLR, p),			p += 4;
 
   if (htab->glink_eh_frame != NULL
diff --git a/ld/testsuite/ld-powerpc/tlsexe.d b/ld/testsuite/ld-powerpc/tlsexe.d
index a455df1802..263551b378 100644
--- a/ld/testsuite/ld-powerpc/tlsexe.d
+++ b/ld/testsuite/ld-powerpc/tlsexe.d
@@ -9,23 +9,23 @@ 
 Disassembly of section \.text:
 
 .* <.*plt_call\.__tls_get_addr(|_opt)>:
-.*	(e9 63 00 00|00 00 63 e9) 	ld      r11,0\(r3\)
+.*	(e8 03 00 00|00 00 03 e8) 	ld      r0,0\(r3\)
 .*	(e9 83 00 08|08 00 83 e9) 	ld      r12,8\(r3\)
+.*	(2c 20 00 00|00 00 20 2c) 	cmpdi   r0,0
 .*	(7c 60 1b 78|78 1b 60 7c) 	mr      r0,r3
-.*	(2c 2b 00 00|00 00 2b 2c) 	cmpdi   r11,0
 .*	(7c 6c 6a 14|14 6a 6c 7c) 	add     r3,r12,r13
 .*	(4d 82 00 20|20 00 82 4d) 	beqlr *
 .*	(7c 03 03 78|78 03 03 7c) 	mr      r3,r0
-.*	(7d 68 02 a6|a6 02 68 7d) 	mflr    r11
-.*	(f9 61 00 20|20 00 61 f9) 	std     r11,32\(r1\)
+.*	(7c 08 02 a6|a6 02 08 7c) 	mflr    r0
+.*	(f8 01 00 20|20 00 01 f8) 	std     r0,32\(r1\)
 .*	(f8 41 00 28|28 00 41 f8) 	std     r2,40\(r1\)
 .*	(e9 82 80 48|48 80 82 e9) 	ld      r12,-32696\(r2\)
 .*	(7d 89 03 a6|a6 03 89 7d) 	mtctr   r12
 .*	(e8 42 80 50|50 80 42 e8) 	ld      r2,-32688\(r2\)
 .*	(4e 80 04 21|21 04 80 4e) 	bctrl
 .*	(e8 41 00 28|28 00 41 e8) 	ld      r2,40\(r1\)
-.*	(e9 61 00 20|20 00 61 e9) 	ld      r11,32\(r1\)
-.*	(7d 68 03 a6|a6 03 68 7d) 	mtlr    r11
+.*	(e8 01 00 20|20 00 01 e8) 	ld      r0,32\(r1\)
+.*	(7c 08 03 a6|a6 03 08 7c) 	mtlr    r0
 .*	(4e 80 00 20|20 00 80 4e) 	blr
 
 .* <._start>:
diff --git a/ld/testsuite/ld-powerpc/tlsexeno.d b/ld/testsuite/ld-powerpc/tlsexeno.d
index 4c5248563b..e0abc876bc 100644
--- a/ld/testsuite/ld-powerpc/tlsexeno.d
+++ b/ld/testsuite/ld-powerpc/tlsexeno.d
@@ -9,23 +9,23 @@ 
 Disassembly of section \.text:
 
 .* <.*plt_call\.__tls_get_addr(|_opt)>:
-.*:	(e9 63 00 00|00 00 63 e9) 	ld      r11,0\(r3\)
+.*:	(e8 03 00 00|00 00 03 e8) 	ld      r0,0\(r3\)
 .*:	(e9 83 00 08|08 00 83 e9) 	ld      r12,8\(r3\)
+.*:	(2c 20 00 00|00 00 20 2c) 	cmpdi   r0,0
 .*:	(7c 60 1b 78|78 1b 60 7c) 	mr      r0,r3
-.*:	(2c 2b 00 00|00 00 2b 2c) 	cmpdi   r11,0
 .*:	(7c 6c 6a 14|14 6a 6c 7c) 	add     r3,r12,r13
-.*:	(4d 82 00 20|20 00 82 4d) 	beqlr
+.*:	(4d 82 00 20|20 00 82 4d) 	beqlr *
 .*:	(7c 03 03 78|78 03 03 7c) 	mr      r3,r0
-.*:	(7d 68 02 a6|a6 02 68 7d) 	mflr    r11
-.*:	(f9 61 00 20|20 00 61 f9) 	std     r11,32\(r1\)
+.*:	(7c 08 02 a6|a6 02 08 7c) 	mflr    r0
+.*:	(f8 01 00 20|20 00 01 f8) 	std     r0,32\(r1\)
 .*:	(f8 41 00 28|28 00 41 f8) 	std     r2,40\(r1\)
 .*:	(e9 82 80 88|88 80 82 e9) 	ld      r12,-32632\(r2\)
 .*:	(7d 89 03 a6|a6 03 89 7d) 	mtctr   r12
 .*:	(e8 42 80 90|90 80 42 e8) 	ld      r2,-32624\(r2\)
 .*:	(4e 80 04 21|21 04 80 4e) 	bctrl
 .*:	(e8 41 00 28|28 00 41 e8) 	ld      r2,40\(r1\)
-.*:	(e9 61 00 20|20 00 61 e9) 	ld      r11,32\(r1\)
-.*:	(7d 68 03 a6|a6 03 68 7d) 	mtlr    r11
+.*:	(e8 01 00 20|20 00 01 e8) 	ld      r0,32\(r1\)
+.*:	(7c 08 03 a6|a6 03 08 7c) 	mtlr    r0
 .*:	(4e 80 00 20|20 00 80 4e) 	blr
 
 .* <\._start>:
diff --git a/ld/testsuite/ld-powerpc/tlsexetoc.d b/ld/testsuite/ld-powerpc/tlsexetoc.d
index 4186fa2d2b..ddec3a9adb 100644
--- a/ld/testsuite/ld-powerpc/tlsexetoc.d
+++ b/ld/testsuite/ld-powerpc/tlsexetoc.d
@@ -9,23 +9,23 @@ 
 Disassembly of section \.text:
 
 .* <.*plt_call\.__tls_get_addr(|_opt)>:
-.*	(e9 63 00 00|00 00 63 e9) 	ld      r11,0\(r3\)
+.*	(e8 03 00 00|00 00 03 e8) 	ld      r0,0\(r3\)
 .*	(e9 83 00 08|08 00 83 e9) 	ld      r12,8\(r3\)
+.*	(2c 20 00 00|00 00 20 2c) 	cmpdi   r0,0
 .*	(7c 60 1b 78|78 1b 60 7c) 	mr      r0,r3
-.*	(2c 2b 00 00|00 00 2b 2c) 	cmpdi   r11,0
 .*	(7c 6c 6a 14|14 6a 6c 7c) 	add     r3,r12,r13
 .*	(4d 82 00 20|20 00 82 4d) 	beqlr *
 .*	(7c 03 03 78|78 03 03 7c) 	mr      r3,r0
-.*	(7d 68 02 a6|a6 02 68 7d) 	mflr    r11
-.*	(f9 61 00 20|20 00 61 f9) 	std     r11,32\(r1\)
+.*	(7c 08 02 a6|a6 02 08 7c) 	mflr    r0
+.*	(f8 01 00 20|20 00 01 f8) 	std     r0,32\(r1\)
 .*	(f8 41 00 28|28 00 41 f8) 	std     r2,40\(r1\)
 .*	(e9 82 80 70|70 80 82 e9) 	ld      r12,-32656\(r2\)
 .*	(7d 89 03 a6|a6 03 89 7d) 	mtctr   r12
 .*	(e8 42 80 78|78 80 42 e8) 	ld      r2,-32648\(r2\)
 .*	(4e 80 04 21|21 04 80 4e) 	bctrl
 .*	(e8 41 00 28|28 00 41 e8) 	ld      r2,40\(r1\)
-.*	(e9 61 00 20|20 00 61 e9) 	ld      r11,32\(r1\)
-.*	(7d 68 03 a6|a6 03 68 7d) 	mtlr    r11
+.*	(e8 01 00 20|20 00 01 e8) 	ld      r0,32\(r1\)
+.*	(7c 08 03 a6|a6 03 08 7c) 	mtlr    r0
 .*	(4e 80 00 20|20 00 80 4e) 	blr
 
 .* <\._start>:
diff --git a/ld/testsuite/ld-powerpc/tlsexetocno.d b/ld/testsuite/ld-powerpc/tlsexetocno.d
index 4f3b7a244d..4ef750db2d 100644
--- a/ld/testsuite/ld-powerpc/tlsexetocno.d
+++ b/ld/testsuite/ld-powerpc/tlsexetocno.d
@@ -9,23 +9,23 @@ 
 Disassembly of section \.text:
 
 .* <.*plt_call\.__tls_get_addr(|_opt)>:
-.*:	(e9 63 00 00|00 00 63 e9) 	ld      r11,0\(r3\)
+.*:	(e8 03 00 00|00 00 03 e8) 	ld      r0,0\(r3\)
 .*:	(e9 83 00 08|08 00 83 e9) 	ld      r12,8\(r3\)
+.*:	(2c 20 00 00|00 00 20 2c) 	cmpdi   r0,0
 .*:	(7c 60 1b 78|78 1b 60 7c) 	mr      r0,r3
-.*:	(2c 2b 00 00|00 00 2b 2c) 	cmpdi   r11,0
 .*:	(7c 6c 6a 14|14 6a 6c 7c) 	add     r3,r12,r13
-.*:	(4d 82 00 20|20 00 82 4d) 	beqlr
+.*:	(4d 82 00 20|20 00 82 4d) 	beqlr *
 .*:	(7c 03 03 78|78 03 03 7c) 	mr      r3,r0
-.*:	(7d 68 02 a6|a6 02 68 7d) 	mflr    r11
-.*:	(f9 61 00 20|20 00 61 f9) 	std     r11,32\(r1\)
+.*:	(7c 08 02 a6|a6 02 08 7c) 	mflr    r0
+.*:	(f8 01 00 20|20 00 01 f8) 	std     r0,32\(r1\)
 .*:	(f8 41 00 28|28 00 41 f8) 	std     r2,40\(r1\)
 .*:	(e9 82 80 70|70 80 82 e9) 	ld      r12,-32656\(r2\)
 .*:	(7d 89 03 a6|a6 03 89 7d) 	mtctr   r12
 .*:	(e8 42 80 78|78 80 42 e8) 	ld      r2,-32648\(r2\)
 .*:	(4e 80 04 21|21 04 80 4e) 	bctrl
 .*:	(e8 41 00 28|28 00 41 e8) 	ld      r2,40\(r1\)
-.*:	(e9 61 00 20|20 00 61 e9) 	ld      r11,32\(r1\)
-.*:	(7d 68 03 a6|a6 03 68 7d) 	mtlr    r11
+.*:	(e8 01 00 20|20 00 01 e8) 	ld      r0,32\(r1\)
+.*:	(7c 08 03 a6|a6 03 08 7c) 	mtlr    r0
 .*:	(4e 80 00 20|20 00 80 4e) 	blr
 
 .* <\._start>:
diff --git a/ld/testsuite/ld-powerpc/tlsopt5.d b/ld/testsuite/ld-powerpc/tlsopt5.d
index a28502797c..596c426bd7 100644
--- a/ld/testsuite/ld-powerpc/tlsopt5.d
+++ b/ld/testsuite/ld-powerpc/tlsopt5.d
@@ -16,22 +16,22 @@  Disassembly of section \.text:
 	\.\.\.
 
 .* <.*\.plt_call\.__tls_get_addr_opt@@GLIBC_2\.22>:
-.*:	(00 00 63 e9|e9 63 00 00) 	ld      r11,0\(r3\)
+.*:	(00 00 03 e8|e8 03 00 00) 	ld      r0,0\(r3\)
 .*:	(08 00 83 e9|e9 83 00 08) 	ld      r12,8\(r3\)
+.*:	(00 00 20 2c|2c 20 00 00) 	cmpdi   r0,0
 .*:	(78 1b 60 7c|7c 60 1b 78) 	mr      r0,r3
-.*:	(00 00 2b 2c|2c 2b 00 00) 	cmpdi   r11,0
 .*:	(14 6a 6c 7c|7c 6c 6a 14) 	add     r3,r12,r13
-.*:	(20 00 82 4d|4d 82 00 20) 	beqlr
+.*:	(20 00 82 4d|4d 82 00 20) 	beqlr *
 .*:	(78 03 03 7c|7c 03 03 78) 	mr      r3,r0
-.*:	(a6 02 68 7d|7d 68 02 a6) 	mflr    r11
-.*:	(08 00 61 f9|f9 61 00 08) 	std     r11,8\(r1\)
+.*:	(a6 02 08 7c|7c 08 02 a6) 	mflr    r0
+.*:	(08 00 01 f8|f8 01 00 08) 	std     r0,8\(r1\)
 .*:	(18 00 41 f8|f8 41 00 18) 	std     r2,24\(r1\)
 .*:	(30 80 82 e9|e9 82 80 30) 	ld      r12,-32720\(r2\)
 .*:	(a6 03 89 7d|7d 89 03 a6) 	mtctr   r12
 .*:	(21 04 80 4e|4e 80 04 21) 	bctrl
 .*:	(18 00 41 e8|e8 41 00 18) 	ld      r2,24\(r1\)
-.*:	(08 00 61 e9|e9 61 00 08) 	ld      r11,8\(r1\)
-.*:	(a6 03 68 7d|7d 68 03 a6) 	mtlr    r11
+.*:	(08 00 01 e8|e8 01 00 08) 	ld      r0,8\(r1\)
+.*:	(a6 03 08 7c|7c 08 03 a6) 	mtlr    r0
 .*:	(20 00 80 4e|4e 80 00 20) 	blr
 	\.\.\.