Make instcombine set explicit alignments on load or store

instructions with alignment 0, so that subsequent passes don't
need to bother checking the TargetData ABI size manually.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110128 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 31 insertions, 14 deletions

diff --git a/test/Transforms/InstCombine/align-addr.ll b/test/Transforms/InstCombine/align-addr.ll
index d8ad5a9864..27916b9860 100644
--- a/test/Transforms/InstCombine/align-addr.ll
+++ b/test/Transforms/InstCombine/align-addr.ll
@@ -1,10 +1,13 @@
-; RUN: opt < %s -instcombine -S | grep {align 16} | count 1
+; RUN: opt < %s -instcombine -S | FileCheck %s
 target datalayout = "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"
 
 ; Instcombine should be able to prove vector alignment in the
 ; presence of a few mild address computation tricks.
 
-define void @foo(i8* %b, i64 %n, i64 %u, i64 %y) nounwind  {
+; CHECK: @test0(
+; CHECK: align 16
+
+define void @test0(i8* %b, i64 %n, i64 %u, i64 %y) nounwind  {
 entry:
   %c = ptrtoint i8* %b to i64
   %d = and i64 %c, -16
@@ -29,3 +32,29 @@ return:
   ret void
 }
 
+; When we see a unaligned load from an insufficiently aligned global or
+; alloca, increase the alignment of the load, turning it into an aligned load.
+
+; CHECK: @test1(
+; CHECK: tmp = load
+; CHECK: GLOBAL{{.*}}align 16
+
+@GLOBAL = internal global [4 x i32] zeroinitializer
+
+define <16 x i8> @test1(<2 x i64> %x) {
+entry:
+	%tmp = load <16 x i8>* bitcast ([4 x i32]* @GLOBAL to <16 x i8>*), align 1
+	ret <16 x i8> %tmp
+}
+
+; When a load or store lacks an explicit alignment, add one.
+
+; CHECK: @test2(
+; CHECK: load double* %p, align 8
+; CHECK: store double %n, double* %p, align 8
+
+define double @test2(double* %p, double %n) nounwind {
+  %t = load double* %p
+  store double %n, double* %p
+  ret double %t
+}
diff --git a/test/Transforms/InstCombine/align-inc.ll b/test/Transforms/InstCombine/align-inc.ll
deleted file mode 100644
index 71512b3a14..0000000000
--- a/test/Transforms/InstCombine/align-inc.ll
+++ /dev/null
@@ -1,12 +0,0 @@
-; RUN: opt < %s -instcombine -S | grep {GLOBAL.*align 16}
-; RUN: opt < %s -instcombine -S | grep {tmp = load}
-target datalayout = "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"
-
-@GLOBAL = internal global [4 x i32] zeroinitializer
-
-define <16 x i8> @foo(<2 x i64> %x) {
-entry:
-	%tmp = load <16 x i8>* bitcast ([4 x i32]* @GLOBAL to <16 x i8>*), align 1
-	ret <16 x i8> %tmp
-}
-