| Colin Cross | 7bb052a | 2015-02-03 12:59:37 -0800 | [diff] [blame^] | 1 | // Copyright 2012 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | #include "a.h" |
| 6 | |
| 7 | #ifndef __ARMEL__ |
| 8 | char * |
| 9 | xgetgoarm(void) |
| 10 | { |
| 11 | return "6"; |
| 12 | } |
| 13 | #else |
| 14 | static void useVFPv3(void); |
| 15 | static void useVFPv1(void); |
| 16 | |
| 17 | char * |
| 18 | xgetgoarm(void) |
| 19 | { |
| 20 | #if defined(__FreeBSD__) |
| 21 | // FreeBSD has broken VFP support |
| 22 | return "5"; |
| 23 | #endif |
| 24 | // NaCl always has VFP support. |
| 25 | if(streq(goos, "nacl") || xtryexecfunc(useVFPv3)) |
| 26 | return "7"; |
| 27 | else if(xtryexecfunc(useVFPv1)) |
| 28 | return "6"; |
| 29 | return "5"; |
| 30 | } |
| 31 | |
| 32 | static void |
| 33 | useVFPv3(void) |
| 34 | { |
| 35 | // try to run VFPv3-only "vmov.f64 d0, #112" instruction |
| 36 | // we can't use that instruction directly, because we |
| 37 | // might be compiling with a soft-float only toolchain. |
| 38 | // |
| 39 | // some newer toolchains are configured to use thumb |
| 40 | // by default, so we need to do some mode changing magic |
| 41 | // here. |
| 42 | // We can use "bx pc; nop" here, but GNU as(1) insists |
| 43 | // on warning us |
| 44 | // "use of r15 in bx in ARM mode is not really useful" |
| 45 | // so we workaround that by using "bx r0" |
| 46 | __asm__ __volatile__ ("mov r0, pc"); |
| 47 | __asm__ __volatile__ ("bx r0"); |
| 48 | __asm__ __volatile__ (".word 0xeeb70b00"); // vmov.f64 d0, #112 |
| 49 | __asm__ __volatile__ (".word 0xe12fff1e"); // bx lr |
| 50 | } |
| 51 | |
| 52 | static void |
| 53 | useVFPv1(void) |
| 54 | { |
| 55 | // try to run "vmov.f64 d0, d0" instruction |
| 56 | // we can't use that instruction directly, because we |
| 57 | // might be compiling with a soft-float only toolchain |
| 58 | // |
| 59 | // some newer toolchains are configured to use thumb |
| 60 | // by default, so we need to do some mode changing magic |
| 61 | // here. |
| 62 | // We can use "bx pc; nop" here, but GNU as(1) insists |
| 63 | // on warning us |
| 64 | // "use of r15 in bx in ARM mode is not really useful" |
| 65 | // so we workaround that by using "bx r0" |
| 66 | __asm__ __volatile__ ("mov r0, pc"); |
| 67 | __asm__ __volatile__ ("bx r0"); |
| 68 | __asm__ __volatile__ (".word 0xeeb00b40"); // vomv.f64 d0, d0 |
| 69 | __asm__ __volatile__ (".word 0xe12fff1e"); // bx lr |
| 70 | } |
| 71 | |
| 72 | #endif |