[llvm] [PowerPC][AIX] Support ByVals with greater alignment then pointer size (PR #93341)

[Sean Fertile via llvm-commits]

================
@@ -0,0 +1,49 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -mtriple powerpc-ibm-aix-xcoff -stop-after=machine-cp -mcpu=pwr7 \
+; RUN:  -mattr=-altivec -verify-machineinstrs < %s | \
+; RUN: FileCheck --check-prefix=32BIT %s
+
+; RUN: llc -mtriple powerpc64-ibm-aix-xcoff -stop-after=machine-cp -mcpu=pwr7 \
+; RUN:  -mattr=-altivec -verify-machineinstrs < %s | \
+; RUN: FileCheck --check-prefix=64BIT %s
+
+%struct.B = type { <8 x i16>, i32, i32, [8 x i8] }
+
+; Function Attrs: nounwind
+define i32 @caller() {
+  ; 32BIT-LABEL: name: caller
+  ; 32BIT: bb.0.entry:
+  ; 32BIT-NEXT:   renamable $r3 = LWZ 28, %stack.0.vs :: (load (s32) from unknown-address + 4)
+  ; 32BIT-NEXT:   STW killed renamable $r3, 60, $r1 :: (store (s32) into unknown-address + 4, basealign 16)
+  ; 32BIT-NEXT:   renamable $r3 = LWZ 24, %stack.0.vs :: (load (s32) from %stack.0.vs + 24, align 8, basealign 16)
+  ; 32BIT-NEXT:   STW killed renamable $r3, 56, $r1 :: (store (s32), align 16)
+  ; 32BIT-NEXT:   ADJCALLSTACKDOWN 64, 0, implicit-def dead $r1, implicit $r1
+  ; 32BIT-NEXT:   renamable $r10 = LWZ 20, %stack.0.vs :: (load (s32) from %stack.0.vs + 20)
+  ; 32BIT-NEXT:   renamable $r9 = LWZ 16, %stack.0.vs :: (load (s32) from %stack.0.vs + 16, align 16)
+  ; 32BIT-NEXT:   renamable $r8 = LWZ 12, %stack.0.vs :: (load (s32) from %stack.0.vs + 12)
+  ; 32BIT-NEXT:   renamable $r7 = LWZ 8, %stack.0.vs :: (load (s32) from %stack.0.vs + 8, align 8)
+  ; 32BIT-NEXT:   renamable $r6 = LWZ 4, %stack.0.vs :: (load (s32) from %stack.0.vs + 4)
+  ; 32BIT-NEXT:   renamable $r5 = LWZ 0, %stack.0.vs :: (load (s32) from %stack.0.vs, align 16)
+  ; 32BIT-NEXT:   $r3 = LI 0
+  ; 32BIT-NEXT:   BL_NOP <mcsymbol .vec_struct_test[PR]>, csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r5, implicit $r6, implicit $r7, implicit $r8, implicit $r9, implicit $r10, implicit $r2, implicit-def $r1, implicit-def $r3
+  ; 32BIT-NEXT:   ADJCALLSTACKUP 64, 0, implicit-def dead $r1, implicit $r1
+  ; 32BIT-NEXT:   BLR implicit $lr, implicit $rm, implicit $r3
+  ;
+  ; 64BIT-LABEL: name: caller
+  ; 64BIT: bb.0.entry:
+  ; 64BIT-NEXT:   ADJCALLSTACKDOWN 112, 0, implicit-def dead $r1, implicit $r1
+  ; 64BIT-NEXT:   renamable $x8 = LD 24, %stack.0.vs :: (load (s64) from %stack.0.vs + 24)
+  ; 64BIT-NEXT:   renamable $x7 = LD 16, %stack.0.vs :: (load (s64) from %stack.0.vs + 16, align 16)
+  ; 64BIT-NEXT:   renamable $x6 = LD 8, %stack.0.vs :: (load (s64) from %stack.0.vs + 8)
+  ; 64BIT-NEXT:   renamable $x5 = LD 0, %stack.0.vs :: (load (s64) from %stack.0.vs, align 16)
+  ; 64BIT-NEXT:   $x3 = LI8 0
+  ; 64BIT-NEXT:   BL8_NOP <mcsymbol .vec_struct_test[PR]>, csr_ppc64, implicit-def dead $lr8, implicit $rm, implicit $x3, implicit $x5, implicit $x6, implicit $x7, implicit $x8, implicit $x2, implicit-def $r1, implicit-def $x3
+  ; 64BIT-NEXT:   ADJCALLSTACKUP 112, 0, implicit-def dead $r1, implicit $r1
+  ; 64BIT-NEXT:   BLR8 implicit $lr8, implicit $rm, implicit $x3
+  entry:
+  %vs = alloca %struct.B, align 16
+  %call = tail call i32 @vec_struct_test(i32 0, %struct.B* nonnull byval(%struct.B) align 16 %vs)
+  ret i32 %call
+}
+
+declare i32 @vec_struct_test(i32, %struct.B* byval(%struct.B) align 16)
----------------
mandlebug wrote:

```suggestion
declare i32 @vec_struct_test(i32, ptr byval(%struct.B) align 16)
```

https://github.com/llvm/llvm-project/pull/93341