[musl] [PATCH] ppc64: check for AltiVec in setjmp/longjmp

[Stijn Tintel <stijn@linux-ipv6.be>]

On machines without AltiVec, the lvx and stvx instructions are not
supported. Use __hwcap to test if AltiVec is supported.

Fixes SIGILL on PowerPC 64 processors without AltiVec support.
Runtime-tested on e5500 and e6500.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
---
 src/setjmp/powerpc64/longjmp.s | 13 ++++++++++++-
 src/setjmp/powerpc64/setjmp.s  | 13 ++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/setjmp/powerpc64/longjmp.s b/src/setjmp/powerpc64/longjmp.s
index 81d45ff6..da7172af 100644
--- a/src/setjmp/powerpc64/longjmp.s
+++ b/src/setjmp/powerpc64/longjmp.s
@@ -56,7 +56,17 @@ longjmp:
 	lfd 30, 38*8(3)
 	lfd 31, 39*8(3)
 
-	# 6) restore vector registers v20-v31
+	# 6) restore vector registers v20-v31 if hardware supports AltiVec
+	mflr 0
+	bl 1f
+	.hidden __hwcap
+	.long __hwcap-.
+1:      mflr 4
+	lwz 5, 0(4)
+	add 4, 4, 5
+	ld 4, 0(4)
+	andis. 4, 4, 0x1000
+	beq 1f
 	addi 3, 3, 40*8
 	lvx 20, 0, 3 ; addi 3, 3, 16
 	lvx 21, 0, 3 ; addi 3, 3, 16
@@ -70,6 +80,7 @@ longjmp:
 	lvx 29, 0, 3 ; addi 3, 3, 16
 	lvx 30, 0, 3 ; addi 3, 3, 16
 	lvx 31, 0, 3
+1:	mtlr 0
 
 	# 7) return r4 ? r4 : 1
 	mr    3,   4
diff --git a/src/setjmp/powerpc64/setjmp.s b/src/setjmp/powerpc64/setjmp.s
index 37683fda..32853693 100644
--- a/src/setjmp/powerpc64/setjmp.s
+++ b/src/setjmp/powerpc64/setjmp.s
@@ -69,7 +69,17 @@ __setjmp_toc:
 	stfd 30, 38*8(3)
 	stfd 31, 39*8(3)
 
-	# 5) store vector registers v20-v31
+	# 5) store vector registers v20-v31 if hardware supports AltiVec
+	mflr 0
+	bl 1f
+	.hidden __hwcap
+	.long __hwcap-.
+1:	mflr 4
+	lwz 5, 0(4)
+	add 4, 4, 5
+	ld 4, 0(4)
+	andis. 4, 4, 0x1000
+	beq 1f
 	addi  3, 3, 40*8
 	stvx 20, 0, 3 ; addi 3, 3, 16
 	stvx 21, 0, 3 ; addi 3, 3, 16
@@ -83,6 +93,7 @@ __setjmp_toc:
 	stvx 29, 0, 3 ; addi 3, 3, 16
 	stvx 30, 0, 3 ; addi 3, 3, 16
 	stvx 31, 0, 3
+1:	mtlr 0
 
 	# 6) return 0
 	li 3, 0
-- 
2.32.0