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| author | pooja2299 <pyadav2299@gmail.com> | 2021-10-20 21:50:28 +0530 |
|---|---|---|
| committer | pooja2299 <pyadav2299@gmail.com> | 2021-10-20 21:50:28 +0530 |
| commit | 8cd7f34abd79e003525a8e1c522c3e6fe8e4e8ef (patch) | |
| tree | d2d4a6371711b4eea6956d6b89f50f337ef20ad2 | |
| parent | 943ed5c6b95054c7efecf2b3d4b4df069907f4dc (diff) | |
| download | llvm-arcpatch-D108319.tar.gz | |
[doc][GlobalISel]Improving generic opcodes for memory operationsarcpatch-D108319
Adding examples for each of the generic opcodes involved in memory operations. Yet to add examples for some of the opcodes.
Reviewed By: gandhi21299
Differential Revision: https://reviews.llvm.org/D108319
| -rw-r--r-- | llvm/docs/GlobalISel/GenericOpcode.rst | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/llvm/docs/GlobalISel/GenericOpcode.rst b/llvm/docs/GlobalISel/GenericOpcode.rst index 899aa06fd069..2809c4b4a96c 100644 --- a/llvm/docs/GlobalISel/GenericOpcode.rst +++ b/llvm/docs/GlobalISel/GenericOpcode.rst @@ -657,6 +657,12 @@ Generic load. Expects a MachineMemOperand in addition to explicit operands. If the result size is larger than the memory size, the high bits are undefined, sign-extended, or zero-extended respectively. +.. code-block:: none + + %load:_(s64) = G_LOAD %ptr(p0) :: (load (s32)) ; High 32 bits are undefined. + %load:_(s64) = G_SEXTLOAD %ptr(p0) :: (load (s32)) ; High 32 bits are sign-extended. + %load:_(s64) = G_ZEXTLOAD %ptr(p0) :: (load (s32)) ; High 32 bits are zero-extended. + Only G_LOAD is valid if the result is a vector type. If the result is larger than the memory size, the high elements are undefined (i.e. this is not a per-element, vector anyextload) @@ -664,9 +670,15 @@ per-element, vector anyextload) G_INDEXED_LOAD ^^^^^^^^^^^^^^ -Generic indexed load. Combines a GEP with a load. $newaddr is set to $base + $offset. +Generic indexed load opcode combines a G_PTR_ADD with a load. + +.. code-block:: none + + $val, $addr = G_INDEXED_LOAD $base, $offset, 1 (IsPre) + +$addr is set to $base + $offset. If $am is 0 (post-indexed), then the value is loaded from $base; if $am is 1 (pre-indexed) -then the value is loaded from $newaddr. +then the value is loaded from $addr. G_INDEXED_SEXTLOAD ^^^^^^^^^^^^^^^^^^ @@ -692,6 +704,10 @@ G_INDEXED_STORE Combines a store with a GEP. See description of G_INDEXED_LOAD for indexing behaviour. +.. code:: none + + $addr = G_INDEXED_STORE $val, $base, $offset + G_ATOMIC_CMPXCHG_WITH_SUCCESS ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |