[AArch64][SME] Rewrite __arm_get_current_vg to preserve required registers #100143
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…sters The documentation for the __arm_get_current_vg support routine specifies that the following registers are call-preserved: - X1-X15, X19-X29 and SP - Z0-Z31 - P0-P15 This patch rewrites the implementation of this routine in compiler-rt, as the current version does not guarantee that these registers will be preserved. See https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#arm-get-current-vg
kmclaughlin-arm
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efriedma-quic
| DEFINE_COMPILERRT_OUTLINE_FUNCTION_UNMANGLED(__arm_get_current_vg) | ||
| .variant_pcs __arm_get_current_vg | ||
| BTI_C | ||
| mov x0, xzr |
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Is this necessary? I'd expect it to be overwritten by the call to __arm_sme_state.
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It does get overwritten, I've removed this
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| __attribute__((target("sve"))) long | ||
| __arm_get_current_vg(void) __arm_streaming_compatible { | ||
| struct SME_STATE State = __arm_sme_state(); |
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Can the definition of this struct and the prototype of __arm_sme_state be removed as well?
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They can indeed :)
| .cfi_offset w30, -8 | ||
| .cfi_offset w29, -16 | ||
| mov x17, x1 | ||
| bl __arm_sme_state |
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Should this call be moved into the 0: branch?
__arm_sme_state call to the '0' branch. - Removed SME_STATE struct from sme-abi-vg.c
sdesmalen-arm
approved these changes
Jul 23, 2024
…t with TPIDR2_SYMBOL
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Should this be backported to 19.x |
Hi @AtariDreams, yes it should be. I will create an issue to backport it. |
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/cherry-pick 6da6772 |
llvmbot
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Jul 25, 2024
…sters (llvm#100143) The documentation for the __arm_get_current_vg support routine specifies that the following registers are call-preserved: - X1-X15, X19-X29 and SP - Z0-Z31 - P0-P15 This patch rewrites the implementation of this routine in compiler-rt, as the current version does not guarantee that these registers will be preserved. (cherry picked from commit 6da6772)
|
/pull-request #100546 |
yuxuanchen1997
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that referenced
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Jul 25, 2024
…sters (#100143) Summary: The documentation for the __arm_get_current_vg support routine specifies that the following registers are call-preserved: - X1-X15, X19-X29 and SP - Z0-Z31 - P0-P15 This patch rewrites the implementation of this routine in compiler-rt, as the current version does not guarantee that these registers will be preserved. Test Plan: Reviewers: Subscribers: Tasks: Tags: Differential Revision: https://phabricator.intern.facebook.com/D60250669
tru
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Jul 26, 2024
…sters (llvm#100143) The documentation for the __arm_get_current_vg support routine specifies that the following registers are call-preserved: - X1-X15, X19-X29 and SP - Z0-Z31 - P0-P15 This patch rewrites the implementation of this routine in compiler-rt, as the current version does not guarantee that these registers will be preserved. (cherry picked from commit 6da6772)
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The documentation for the __arm_get_current_vg support routine specifies
that the following registers are call-preserved:
This patch rewrites the implementation of this routine in compiler-rt, as
the current version does not guarantee that these registers will be preserved.