AsmWriter: Write alloca array size explicitly (and -instcombine fixup)

Write the `alloca` array size explicitly when it's non-canonical.
Previously, if the array size was `iX 1` (where X is not 32), the type
would mutate to `i32` when round-tripping through assembly.

The testcase I added fails in `verify-uselistorder` (as well as
`FileCheck`), since the use-lists for `i32 1` and `i64 1` change.
(Manman Ren came across this when running `verify-uselistorder` on some
non-trivial, optimized code as part of PR5680.)

The type mutation started with r104911, which allowed array sizes to be
something other than an `i32`.  Starting with r204945, we
"canonicalized" to `i64` on 64-bit platforms -- and then on every
round-trip through assembly, mutated back to `i32`.

I bundled a fixup for `-instcombine` to avoid r204945 on scalar
allocations.  (There wasn't a clean way to sequence this into two
commits, since the assembly change on its own caused testcase churn, and
the `-instcombine` change can't be tested without the assembly changes.)

An obvious alternative fix -- change `AllocaInst::AllocaInst()`,
`AsmWriter` and `LLParser` to treat `intptr_t` as the canonical type for
scalar allocations -- was rejected out of hand, since this required
teaching them each about the data layout.

A follow-up commit will add an `-instcombine` to canonicalize the scalar
allocation array size to `i32 1` rather than leaving `iX 1` alone.

rdar://problem/20075773

llvm-svn: 232200

1 files changed, 16 insertions, 3 deletions

diff --git a/llvm/test/Transforms/InstCombine/alloca.ll b/llvm/test/Transforms/InstCombine/alloca.ll
index 105029fb699..db26218f3b8 100644
--- a/llvm/test/Transforms/InstCombine/alloca.ll
+++ b/llvm/test/Transforms/InstCombine/alloca.ll
@@ -1,6 +1,6 @@
-; RUN: opt < %s -instcombine -S -default-data-layout="E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" | FileCheck %s
-; RUN: opt < %s -instcombine -S -default-data-layout="E-p:32:32:32-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" | FileCheck %s -check-prefix=P32
-; RUN: opt < %s -instcombine -S | FileCheck %s -check-prefix=NODL
+; RUN: opt < %s -instcombine -S -default-data-layout="E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" | FileCheck %s -check-prefix=CHECK -check-prefix=ALL
+; RUN: opt < %s -instcombine -S -default-data-layout="E-p:32:32:32-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" | FileCheck %s -check-prefix=P32 -check-prefix=ALL
+; RUN: opt < %s -instcombine -S | FileCheck %s -check-prefix=NODL -check-prefix=ALL
 
 
 declare void @use(...)
@@ -150,3 +150,16 @@ entry:
   call void @llvm.stackrestore(i8* %inalloca.save)
   ret void
 }
+
+define void @test10() {
+entry:
+; ALL-LABEL: @test10(
+; ALL: %v32 = alloca i1, align 8
+; ALL: %v64 = alloca i1, i64 1, align 8
+; ALL: %v33 = alloca i1, i33 1, align 8
+  %v32 = alloca i1, align 8
+  %v64 = alloca i1, i64 1, align 8
+  %v33 = alloca i1, i33 1, align 8
+  call void (...)* @use(i1* %v32, i1* %v64, i1* %v33)
+  ret void
+}