| /* |
| * Copyright (c) 2013 The Native Client Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| /* |
| * Rounding mode control field is bits [11:10] in the x87 |
| * control word, and bits [14:13] in the SSE control word. |
| * This function takes in %ecx the two-bit value pre-shifted to |
| * bits [11:10] and sets both control words at the appropriate bits. |
| * |
| * The bit patterns for X86 are: |
| * 0b00 Round to Nearest (RN) mode |
| * 0b10 Round towards Plus Infinity (RP) mode |
| * 0b01 Round towards Minus Infinity (RM) mode |
| * 0b11 Round towards Zero (RZ) mode |
| */ |
| .p2align 5 |
| set_rounding_control_field: |
| /* First set the 87 control word */ |
| #if defined(__x86_64__) |
| fnstcw -8(%rsp) # Use red zone. |
| movl -8(%rsp), %eax |
| #else |
| sub $12, %esp |
| fnstcw 0(%esp) |
| movl 0(%esp), %eax |
| #endif |
| andl $0xfffff3ff, %eax |
| orl %ecx, %eax |
| #if defined(__x86_64__) |
| movl %eax, -8(%rsp) |
| fldcw -8(%rsp) |
| #else |
| movl %eax, 0(%esp) |
| fldcw 0(%esp) |
| #endif |
| /* Then set the SSE control word w/ same pattern, but shifted. */ |
| #if defined(__x86_64__) |
| stmxcsr -8(%rsp) |
| movl -8(%rsp), %eax |
| #else |
| stmxcsr 0(%esp) |
| movl 0(%esp), %eax |
| #endif |
| andl $0xffff9fff, %eax |
| shl $3, %ecx |
| orl %ecx, %eax |
| #if defined(__x86_64__) |
| movl %eax, -8(%rsp) |
| ldmxcsr -8(%rsp) |
| #else |
| movl %eax, 0(%esp) |
| ldmxcsr 0(%esp) |
| add $12, %esp |
| #endif |
| naclret |
| |
| .p2align 5 |
| .global set_round_toward_nearest |
| set_round_toward_nearest: |
| /* Use a fast-cc + tail call to avoid stack manipulation/alignment */ |
| movl $0, %ecx |
| jmp set_rounding_control_field |
| |
| .p2align 5 |
| .global set_round_toward_plus_infinity |
| set_round_toward_plus_infinity: |
| movl $0x800, %ecx |
| jmp set_rounding_control_field |
| |
| .p2align 5 |
| .global set_round_toward_minus_infinity |
| set_round_toward_minus_infinity: |
| movl $0x400, %ecx |
| jmp set_rounding_control_field |
| |
| .p2align 5 |
| .global set_round_toward_zero |
| set_round_toward_zero: |
| movl $0xc00, %ecx |
| jmp set_rounding_control_field |
