[PATCH] D65535: [ArgPromo][Tests] Examples to show missing 'byval' argument propagation

[Johannes Doerfert via Phabricator via llvm-commits]

jdoerfert created this revision.
jdoerfert added reviewers: vsk, dblaikie, davidxl, tejohnson, tstellar, echristo, chandlerc, efriedma, lebedev.ri.
Herald added a subscriber: bollu.
Herald added a project: LLVM.

This adds a test to show that we miss propagating a byval array.
Similar problem cases are already in the code base, see

  https://bugs.llvm.org/show_bug.cgi?id=42852


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D65535

Files:
  llvm/test/Transforms/ArgumentPromotion/byval.ll


Index: llvm/test/Transforms/ArgumentPromotion/byval.ll
===================================================================
--- llvm/test/Transforms/ArgumentPromotion/byval.ll
+++ llvm/test/Transforms/ArgumentPromotion/byval.ll
@@ -7,6 +7,10 @@
 
 define internal void @f(%struct.ss* byval  %b) nounwind  {
 entry:
+; CHECK-LABEL: define internal void @f(i32 %b.0, i64 %b.1)
+; CHECK: alloca %struct.ss{{$}}
+; CHECK: store i32 %b.0
+; CHECK: store i64 %b.1
   %tmp = getelementptr %struct.ss, %struct.ss* %b, i32 0, i32 0
   %tmp1 = load i32, i32* %tmp, align 4
   %tmp2 = add i32 %tmp1, 1
@@ -14,13 +18,13 @@
   ret void
 }
 
-; CHECK-LABEL: define internal void @f(i32 %b.0, i64 %b.1)
-; CHECK: alloca %struct.ss{{$}}
-; CHECK: store i32 %b.0
-; CHECK: store i64 %b.1
-
 define internal void @g(%struct.ss* byval align 32 %b) nounwind {
 entry:
+
+; CHECK-LABEL: define internal void @g(i32 %b.0, i64 %b.1)
+; CHECK: alloca %struct.ss, align 32
+; CHECK: store i32 %b.0
+; CHECK: store i64 %b.1
   %tmp = getelementptr %struct.ss, %struct.ss* %b, i32 0, i32 0
   %tmp1 = load i32, i32* %tmp, align 4
   %tmp2 = add i32 %tmp1, 1
@@ -28,13 +32,19 @@
   ret void
 }
 
-; CHECK-LABEL: define internal void @g(i32 %b.0, i64 %b.1)
-; CHECK: alloca %struct.ss, align 32
-; CHECK: store i32 %b.0
-; CHECK: store i64 %b.1
+define internal void @h([2 x i32]* byval %b) nounwind {
+entry:
+; Even if we do not access the first element we can promote this array.
+  %tmp = getelementptr [2 x i32], [2 x i32]* %b, i32 0, i32 1
+  %tmp1 = load i32, i32* %tmp, align 4
+  %tmp2 = add i32 %tmp1, 1
+  store i32 %tmp2, i32* %tmp, align 4
+  ret void
+}
 
 define i32 @main() nounwind  {
 entry:
+  %A = alloca [2 x i32]
   %S = alloca %struct.ss
   %tmp1 = getelementptr %struct.ss, %struct.ss* %S, i32 0, i32 0
   store i32 1, i32* %tmp1, align 8
@@ -42,6 +52,10 @@
   store i64 2, i64* %tmp4, align 4
   call void @f(%struct.ss* byval %S) nounwind
   call void @g(%struct.ss* byval %S) nounwind
+; Verify we unpack the byval array.
+; FIXME: this sould be: call void @h(i32 %{{[a-zA-Z._0-9]*}}, i32 %{{[a-zA-Z._0-9]*}})
+; CHECK: call void @h([2 x i32]* byval %A)
+  call void @h([2 x i32]* byval %A) nounwind
   ret i32 0
 }
 


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