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author | Anton Samokhvalov <pg83@yandex.ru> | 2022-02-10 16:45:15 +0300 |
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committer | Daniil Cherednik <dcherednik@yandex-team.ru> | 2022-02-10 16:45:15 +0300 |
commit | 72cb13b4aff9bc9cf22e49251bc8fd143f82538f (patch) | |
tree | da2c34829458c7d4e74bdfbdf85dff449e9e7fb8 /contrib/libs/cxxsupp/builtins/arm/switch16.S | |
parent | 778e51ba091dc39e7b7fcab2b9cf4dbedfb6f2b5 (diff) | |
download | ydb-72cb13b4aff9bc9cf22e49251bc8fd143f82538f.tar.gz |
Restoring authorship annotation for Anton Samokhvalov <pg83@yandex.ru>. Commit 1 of 2.
Diffstat (limited to 'contrib/libs/cxxsupp/builtins/arm/switch16.S')
-rw-r--r-- | contrib/libs/cxxsupp/builtins/arm/switch16.S | 88 |
1 files changed, 44 insertions, 44 deletions
diff --git a/contrib/libs/cxxsupp/builtins/arm/switch16.S b/contrib/libs/cxxsupp/builtins/arm/switch16.S index 3c3a6b1061..4350d4fee3 100644 --- a/contrib/libs/cxxsupp/builtins/arm/switch16.S +++ b/contrib/libs/cxxsupp/builtins/arm/switch16.S @@ -1,44 +1,44 @@ -//===-- switch.S - Implement switch* --------------------------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is dual licensed under the MIT and the University of Illinois Open -// Source Licenses. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "../assembly.h" - -// -// When compiling switch statements in thumb mode, the compiler -// can use these __switch* helper functions The compiler emits a blx to -// the __switch* function followed by a table of displacements for each -// case statement. On entry, R0 is the index into the table. The __switch* -// function uses the return address in lr to find the start of the table. -// The first entry in the table is the count of the entries in the table. -// It then uses R0 to index into the table and get the displacement of the -// address to jump to. If R0 is greater than the size of the table, it jumps -// to the last entry in the table. Each displacement in the table is actually -// the distance from lr to the label, thus making the tables PIC. - - - .text - .syntax unified - -// -// The table contains signed 2-byte sized elements which are 1/2 the distance -// from lr to the target label. -// - .p2align 2 -DEFINE_COMPILERRT_PRIVATE_FUNCTION(__switch16) - ldrh ip, [lr, #-1] // get first 16-bit word in table - cmp r0, ip // compare with index - add r0, lr, r0, lsl #1 // compute address of element in table - add ip, lr, ip, lsl #1 // compute address of last element in table - ite lo - ldrshlo r0, [r0, #1] // load 16-bit element if r0 is in range - ldrshhs r0, [ip, #1] // load 16-bit element if r0 out of range - add ip, lr, r0, lsl #1 // compute label = lr + element*2 - bx ip // jump to computed label -END_COMPILERRT_FUNCTION(__switch16) - +//===-- switch.S - Implement switch* --------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "../assembly.h" + +// +// When compiling switch statements in thumb mode, the compiler +// can use these __switch* helper functions The compiler emits a blx to +// the __switch* function followed by a table of displacements for each +// case statement. On entry, R0 is the index into the table. The __switch* +// function uses the return address in lr to find the start of the table. +// The first entry in the table is the count of the entries in the table. +// It then uses R0 to index into the table and get the displacement of the +// address to jump to. If R0 is greater than the size of the table, it jumps +// to the last entry in the table. Each displacement in the table is actually +// the distance from lr to the label, thus making the tables PIC. + + + .text + .syntax unified + +// +// The table contains signed 2-byte sized elements which are 1/2 the distance +// from lr to the target label. +// + .p2align 2 +DEFINE_COMPILERRT_PRIVATE_FUNCTION(__switch16) + ldrh ip, [lr, #-1] // get first 16-bit word in table + cmp r0, ip // compare with index + add r0, lr, r0, lsl #1 // compute address of element in table + add ip, lr, ip, lsl #1 // compute address of last element in table + ite lo + ldrshlo r0, [r0, #1] // load 16-bit element if r0 is in range + ldrshhs r0, [ip, #1] // load 16-bit element if r0 out of range + add ip, lr, r0, lsl #1 // compute label = lr + element*2 + bx ip // jump to computed label +END_COMPILERRT_FUNCTION(__switch16) + |