[llvm-branch-commits] [llvm] GlobalISel: Improve MMO extended LLT caclulation from size (PR #196398)

[Petar Avramovic via llvm-branch-commits]

https://github.com/petar-avramovic updated https://github.com/llvm/llvm-project/pull/196398

>From d7babc2fae6fcbd3d10d14071a5af6649e2c4f10 Mon Sep 17 00:00:00 2001
From: Petar Avramovic <Petar.Avramovic at amd.com>
Date: Thu, 7 May 2026 20:56:43 +0200
Subject: [PATCH] GlobalISel: Improve MMO extended LLT caclulation from size

---
 llvm/include/llvm/CodeGen/MachineFunction.h       | 15 +++++++++------
 .../CodeGen/AArch64/GlobalISel/legalize-and.mir   |  4 ++--
 .../AArch64/GlobalISel/legalize-load-store.mir    |  4 ++--
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/MachineFunction.h b/llvm/include/llvm/CodeGen/MachineFunction.h
index d620ae5137eba..5e34eab8c57e7 100644
--- a/llvm/include/llvm/CodeGen/MachineFunction.h
+++ b/llvm/include/llvm/CodeGen/MachineFunction.h
@@ -1158,12 +1158,15 @@ class LLVM_ABI MachineFunction {
                                           int64_t Offset, LLT Ty);
   MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
                                           int64_t Offset, LocationSize Size) {
-    return getMachineMemOperand(
-        MMO, Offset,
-        !Size.isPrecise() ? LLT()
-        : Size.isScalable()
-            ? LLT::scalable_vector(1, 8 * Size.getValue().getKnownMinValue())
-            : LLT::scalar(8 * Size.getValue().getKnownMinValue()));
+    if (!Size.isPrecise())
+      return getMachineMemOperand(MMO, Offset, LLT());
+
+    unsigned SizeInBits = 8 * Size.getValue().getKnownMinValue();
+    LLT Ty = Size.isScalable() ? LLT::scalable_vector(1, SizeInBits)
+             : MMO->getType().isPointerOrPointerVector()
+                 ? LLT::scalar(SizeInBits)
+                 : MMO->getType().changeElementSize(SizeInBits);
+    return getMachineMemOperand(MMO, Offset, Ty);
   }
   MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
                                           int64_t Offset, uint64_t Size) {
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-and.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-and.mir
index 252960568fe94..683e5523c9ad9 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-and.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-and.mir
@@ -65,8 +65,8 @@ body:             |
     ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(i32) = G_LSHR [[TRUNC]], [[C5]](i64)
     ; CHECK-NEXT: [[C6:%[0-9]+]]:_(i64) = G_CONSTANT i64 2
     ; CHECK-NEXT: [[PTR_ADD4:%[0-9]+]]:_(p0) = nuw inbounds G_PTR_ADD [[PTR_ADD3]], [[C6]](i64)
-    ; CHECK-NEXT: G_STORE [[TRUNC]](i32), [[PTR_ADD3]](p0) :: (store (s16) into unknown-address + 8, align 8)
-    ; CHECK-NEXT: G_STORE [[LSHR]](i32), [[PTR_ADD4]](p0) :: (store (s8) into unknown-address + 10, align 2)
+    ; CHECK-NEXT: G_STORE [[TRUNC]](i32), [[PTR_ADD3]](p0) :: (store (i16) into unknown-address + 8, align 8)
+    ; CHECK-NEXT: G_STORE [[LSHR]](i32), [[PTR_ADD4]](p0) :: (store (i8) into unknown-address + 10, align 2)
     %ptr:_(p0) = COPY $x0
     %a:_(i88) = G_LOAD %ptr(p0) :: (load (s88))
     %b:_(i88) = G_LOAD %ptr(p0) :: (load (s88))
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-load-store.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-load-store.mir
index ab4ecc5241a26..15c42aab0781b 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-load-store.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-load-store.mir
@@ -650,8 +650,8 @@ body:             |
     ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(i32) = G_LSHR [[TRUNC]], [[C5]](i64)
     ; CHECK-NEXT: [[C6:%[0-9]+]]:_(i64) = G_CONSTANT i64 2
     ; CHECK-NEXT: [[PTR_ADD3:%[0-9]+]]:_(p0) = nuw inbounds G_PTR_ADD [[PTR_ADD2]], [[C6]](i64)
-    ; CHECK-NEXT: G_STORE [[TRUNC]](i32), [[PTR_ADD2]](p0) :: (store (s16) into unknown-address + 8, align 8)
-    ; CHECK-NEXT: G_STORE [[LSHR]](i32), [[PTR_ADD3]](p0) :: (store (s8) into unknown-address + 10, align 2)
+    ; CHECK-NEXT: G_STORE [[TRUNC]](i32), [[PTR_ADD2]](p0) :: (store (i16) into unknown-address + 8, align 8)
+    ; CHECK-NEXT: G_STORE [[LSHR]](i32), [[PTR_ADD3]](p0) :: (store (i8) into unknown-address + 10, align 2)
     ; CHECK-NEXT: RET_ReallyLR
     %ptr:_(p0) = COPY $x0
     %load:_(s88) = G_LOAD %ptr(p0) :: (load (s88))