From 9f290a49bf9ee247d540d3c83875288a7991699c Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Mon, 9 Nov 2015 22:36:38 -0500
Subject: remove non-working pre-armv4t support from arm asm

the idea of the three-instruction sequence being removed was to be
able to return to thumb code when used on armv4t+ from a thumb caller,
but also to be able to run on armv4 without the bx instruction
available (in which case the low bit of lr would always be 0).
however, without compiler support for generating such a sequence from
C code, which does not exist and which there is unlikely to be
interest in implementing, there is little point in having it in the
asm, and it would likely be easier to add pre-armv4t support via
enhanced linker handling of R_ARM_V4BX than at the compiler level.

removing this code simplifies adding support for building libc in
thumb2-only form (for cortex-m).
---
 src/internal/arm/syscall.s  | 2 --
 src/setjmp/arm/longjmp.s    | 4 +---
 src/setjmp/arm/setjmp.s     | 4 +---
 src/string/armel/memcpy.s   | 4 ----
 src/thread/arm/clone.s      | 2 --
 src/thread/arm/syscall_cp.s | 2 --
 6 files changed, 2 insertions(+), 16 deletions(-)

(limited to 'src')

diff --git a/src/internal/arm/syscall.s b/src/internal/arm/syscall.s
index 2028456c..28cb17ba 100644
--- a/src/internal/arm/syscall.s
+++ b/src/internal/arm/syscall.s
@@ -11,6 +11,4 @@ __syscall:
 	ldmfd ip,{r3,r4,r5,r6}
 	svc 0
 	ldmfd sp!,{r4,r5,r6,r7}
-	tst lr,#1
-	moveq pc,lr
 	bx lr
diff --git a/src/setjmp/arm/longjmp.s b/src/setjmp/arm/longjmp.s
index 82bce832..7db93e8a 100644
--- a/src/setjmp/arm/longjmp.s
+++ b/src/setjmp/arm/longjmp.s
@@ -33,9 +33,7 @@ longjmp:
 	ldcl p1, cr13, [ip], #8
 	ldcl p1, cr14, [ip], #8
 	ldcl p1, cr15, [ip], #8
-3:	tst lr,#1
-	moveq pc,lr
-	bx lr
+3:	bx lr
 
 .hidden __hwcap
 1:	.word __hwcap-1b
diff --git a/src/setjmp/arm/setjmp.s b/src/setjmp/arm/setjmp.s
index 32db7d87..61425ad5 100644
--- a/src/setjmp/arm/setjmp.s
+++ b/src/setjmp/arm/setjmp.s
@@ -35,9 +35,7 @@ setjmp:
 	stcl p1, cr13, [ip], #8
 	stcl p1, cr14, [ip], #8
 	stcl p1, cr15, [ip], #8
-3:	tst lr,#1
-	moveq pc,lr
-	bx lr
+3:	bx lr
 
 .hidden __hwcap
 1:	.word __hwcap-1b
diff --git a/src/string/armel/memcpy.s b/src/string/armel/memcpy.s
index 54164030..b16be0d6 100644
--- a/src/string/armel/memcpy.s
+++ b/src/string/armel/memcpy.s
@@ -189,8 +189,6 @@ less_than_32_left:
 	/* we're done! restore everything and return */
 1:      ldmfd   sp!, {r5-r11}
 	ldmfd   sp!, {r0, r4, lr}
-	tst     lr, #1
-	moveq   pc, lr
 	bx      lr
 
 	/********************************************************************/
@@ -378,6 +376,4 @@ copy_last_3_and_return:
 	/* we're done! restore sp and spilled registers and return */
 	add     sp,  sp, #28
 	ldmfd   sp!, {r0, r4, lr}
-	tst     lr, #1
-	moveq   pc, lr
 	bx      lr
diff --git a/src/thread/arm/clone.s b/src/thread/arm/clone.s
index d146999b..b7fb788b 100644
--- a/src/thread/arm/clone.s
+++ b/src/thread/arm/clone.s
@@ -15,8 +15,6 @@ __clone:
 	tst r0,r0
 	beq 1f
 	ldmfd sp!,{r4,r5,r6,r7}
-	tst lr,#1
-	moveq pc,lr
 	bx lr
 
 1:	mov r0,r6
diff --git a/src/thread/arm/syscall_cp.s b/src/thread/arm/syscall_cp.s
index 96ce6135..64528b39 100644
--- a/src/thread/arm/syscall_cp.s
+++ b/src/thread/arm/syscall_cp.s
@@ -22,8 +22,6 @@ __cp_begin:
 	svc 0
 __cp_end:
 	ldmfd sp!,{r4,r5,r6,r7,lr}
-	tst lr,#1
-	moveq pc,lr
 	bx lr
 __cp_cancel:
 	ldmfd sp!,{r4,r5,r6,r7,lr}
-- 
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