| // Copyright 2019 The SwiftShader Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #if defined(__x86_64__) |
| |
| #define YARN_BUILD_ASM 1 |
| #include "OSFiber_asm_x64.h" |
| |
| // void yarn_fiber_swap(yarn_fiber_context* from, const yarn_fiber_context* to) |
| // rdi: from |
| // rsi: to |
| .text |
| .global YARN_ASM_SYMBOL(yarn_fiber_swap) |
| .align 4 |
| YARN_ASM_SYMBOL(yarn_fiber_swap): |
| |
| // Save context 'from' |
| |
| // Store callee-preserved registers |
| movq %rbx, YARN_REG_RBX(%rdi) |
| movq %rbp, YARN_REG_RBP(%rdi) |
| movq %r12, YARN_REG_R12(%rdi) |
| movq %r13, YARN_REG_R13(%rdi) |
| movq %r14, YARN_REG_R14(%rdi) |
| movq %r15, YARN_REG_R15(%rdi) |
| |
| movq (%rsp), %rcx /* call stores the return address on the stack before jumping */ |
| movq %rcx, YARN_REG_RIP(%rdi) |
| leaq 8(%rsp), %rcx /* skip the pushed return address */ |
| movq %rcx, YARN_REG_RSP(%rdi) |
| |
| // Load context 'to' |
| movq %rsi, %r8 |
| |
| // Load callee-preserved registers |
| movq YARN_REG_RBX(%r8), %rbx |
| movq YARN_REG_RBP(%r8), %rbp |
| movq YARN_REG_R12(%r8), %r12 |
| movq YARN_REG_R13(%r8), %r13 |
| movq YARN_REG_R14(%r8), %r14 |
| movq YARN_REG_R15(%r8), %r15 |
| |
| // Load first two call parameters |
| movq YARN_REG_RDI(%r8), %rdi |
| movq YARN_REG_RSI(%r8), %rsi |
| |
| // Load stack pointer |
| movq YARN_REG_RSP(%r8), %rsp |
| |
| // Load instruction pointer, and jump |
| movq YARN_REG_RIP(%r8), %rcx |
| jmp *%rcx |
| |
| #endif // defined(__x86_64__) |
