arm/sysv: reverted clang VFP mitigation (#747)

Since commit e3d2812ce43940aacae5bab2d0e965278cb1e7ea,
seperate instructions were used when compiling under clang,
as clang didn't allow the directives at the time. This mitigation
now causes compilation to fail under clang 10, as described by
https://github.com/libffi/libffi/issues/607. Now that
clang supports the LDC and SDC instructions, this mitigation
has been reverted.

Co-authored-by: Brett Warren <brett.warren@arm.com>

diff --git a/src/arm/sysv.S b/src/arm/sysv.S
index fb36213c6805fa5017154328e094daeaf902a0c5..e4272a103c542da193759ed3680e4e2bbb80c6b1 100644 (file)
--- a/src/arm/sysv.S
+++ b/src/arm/sysv.S
@@ -142,13 +142,8 @@ ARM_FUNC_START(ffi_call_VFP)
 
        cmp     r3, #3                  @ load only d0 if possible
        ite     le
-#ifdef __clang__
-       vldrle d0, [r0]
-       vldmgt r0, {d0-d7}
-#else
        ldcle   p11, cr0, [r0]          @ vldrle d0, [r0]
        ldcgt   p11, cr0, [r0], {16}    @ vldmgt r0, {d0-d7}
-#endif
        add     r0, r0, #64             @ discard the vfp register args
        /* FALLTHRU */
 ARM_FUNC_END(ffi_call_VFP)
@@ -193,25 +188,13 @@ ARM_FUNC_START(ffi_call_SYSV)
 #endif
 0:
 E(ARM_TYPE_VFP_S)
-#ifdef __clang__
-       vstr s0, [r2]
-#else
        stc     p10, cr0, [r2]          @ vstr s0, [r2]
-#endif
        pop     {fp,pc}
 E(ARM_TYPE_VFP_D)
-#ifdef __clang__
-       vstr d0, [r2]
-#else
        stc     p11, cr0, [r2]          @ vstr d0, [r2]
-#endif
        pop     {fp,pc}
 E(ARM_TYPE_VFP_N)
-#ifdef __clang__
-       vstm r2, {d0-d3}
-#else
        stc     p11, cr0, [r2], {8}     @ vstm r2, {d0-d3}
-#endif
        pop     {fp,pc}
 E(ARM_TYPE_INT64)
        str     r1, [r2, #4]
@@ -320,11 +303,7 @@ ARM_FUNC_START(ffi_closure_VFP)
        add     ip, sp, #16
        sub     sp, sp, #64+32                  @ allocate frame
        cfi_adjust_cfa_offset(64+32)
-#ifdef __clang__
-       vstm sp, {d0-d7}
-#else
        stc     p11, cr0, [sp], {16}            @ vstm sp, {d0-d7}
-#endif
        stmdb   sp!, {ip,lr}
 
        /* See above.  */
@@ -358,25 +337,13 @@ ARM_FUNC_START_LOCAL(ffi_closure_ret)
        cfi_rel_offset(lr, 4)
 0:
 E(ARM_TYPE_VFP_S)
-#ifdef __clang__
-       vldr s0, [r2]
-#else
        ldc     p10, cr0, [r2]                  @ vldr s0, [r2]
-#endif
        b       call_epilogue
 E(ARM_TYPE_VFP_D)
-#ifdef __clang__
-       vldr d0, [r2]
-#else
        ldc     p11, cr0, [r2]                  @ vldr d0, [r2]
-#endif
        b       call_epilogue
 E(ARM_TYPE_VFP_N)
-#ifdef __clang__
-       vldm r2, {d0-d3}
-#else
        ldc     p11, cr0, [r2], {8}             @ vldm r2, {d0-d3}
-#endif
        b       call_epilogue
 E(ARM_TYPE_INT64)
        ldr     r1, [r2, #4]