[llvm] a501d06 - [Attributor] Only manifest pointer operand for `StoreInst` in `AAAddressSpace` (#65708)

[via llvm-commits]

Author: Shilei Tian
Date: 2023-09-08T15:24:25-04:00
New Revision: a501d06fcbe97cf5c577d23fbdb9272ba7d6fa83

URL: https://github.com/llvm/llvm-project/commit/a501d06fcbe97cf5c577d23fbdb9272ba7d6fa83
DIFF: https://github.com/llvm/llvm-project/commit/a501d06fcbe97cf5c577d23fbdb9272ba7d6fa83.diff

LOG: [Attributor] Only manifest pointer operand for `StoreInst` in `AAAddressSpace` (#65708)

`AAAddressSpace` currently only works for `LoadInst` and `StoreInst`
currently. For `StoreInst`, the corresponding use can be the pointer
operand, or value operand, or both. When it is used as value operand, it
can prevent `AMDGPUPromoteAlloca` from optimization in certain cases.
This patch changes the manifest method such that only pointer operand
will be rewritten.

Added: 
    

Modified: 
    llvm/lib/Transforms/IPO/AttributorAttributes.cpp
    llvm/test/Transforms/Attributor/address_space_info.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 2f6d8c65c541676..03b5dc3899ac8f8 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -12550,8 +12550,13 @@ struct AAAddressSpaceImpl : public AAAddressSpace {
       // CGSCC if the AA is run on CGSCC instead of the entire module.
       if (!A.isRunOn(Inst->getFunction()))
         return true;
-      if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst))
+      if (isa<LoadInst>(Inst))
         MakeChange(Inst, const_cast<Use &>(U));
+      if (auto *SI = dyn_cast<StoreInst>(Inst)) {
+        // We only make changes if the use is the pointer operand.
+        if (U.getOperandNo() == 1)
+          MakeChange(Inst, const_cast<Use &>(U));
+      }
       return true;
     };
 

diff  --git a/llvm/test/Transforms/Attributor/address_space_info.ll b/llvm/test/Transforms/Attributor/address_space_info.ll
index 076060a2763c2af..d865ae1eae39b4b 100644
--- a/llvm/test/Transforms/Attributor/address_space_info.ll
+++ b/llvm/test/Transforms/Attributor/address_space_info.ll
@@ -20,8 +20,7 @@ define internal void @_Z12global_writePi(ptr noundef %p) #0 {
 ; CHECK-SAME: (ptr nofree noundef nonnull writeonly align 4 dereferenceable(8) [[P:%.*]]) #[[ATTR0:[0-9]+]] {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TMP0:%.*]] = addrspacecast ptr [[P]] to ptr addrspace(1)
-; CHECK-NEXT:    [[TMP1:%.*]] = addrspacecast ptr [[P]] to ptr addrspace(1)
-; CHECK-NEXT:    store ptr addrspace(1) [[TMP0]], ptr addrspace(1) [[TMP1]], align 4
+; CHECK-NEXT:    store ptr [[P]], ptr addrspace(1) [[TMP0]], align 4
 ; CHECK-NEXT:    ret void
 ;
 entry: