[llvm-branch-commits] [llvm] 8cd7f34 - [doc][GlobalISel]Improving generic opcodes for memory operations

[via llvm-branch-commits]

Author: pooja2299
Date: 2021-10-20T21:50:28+05:30
New Revision: 8cd7f34abd79e003525a8e1c522c3e6fe8e4e8ef

URL: https://github.com/llvm/llvm-project/commit/8cd7f34abd79e003525a8e1c522c3e6fe8e4e8ef
DIFF: https://github.com/llvm/llvm-project/commit/8cd7f34abd79e003525a8e1c522c3e6fe8e4e8ef.diff

LOG: [doc][GlobalISel]Improving generic opcodes for memory operations

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

Added: 
    

Modified: 
    llvm/docs/GlobalISel/GenericOpcode.rst

Removed: 
    


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diff  --git a/llvm/docs/GlobalISel/GenericOpcode.rst b/llvm/docs/GlobalISel/GenericOpcode.rst
index 899aa06fd0699..2809c4b4a96c2 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
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^