diff options
Diffstat (limited to 'test/Transforms/InstCombine/constant-fold-alias.ll')
| -rw-r--r-- | test/Transforms/InstCombine/constant-fold-alias.ll | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/constant-fold-alias.ll b/test/Transforms/InstCombine/constant-fold-alias.ll new file mode 100644 index 0000000..13da0f4 --- /dev/null +++ b/test/Transforms/InstCombine/constant-fold-alias.ll @@ -0,0 +1,40 @@ +; RUN: opt -S < %s -instcombine | FileCheck %s + +target datalayout = "e-p1:16:16-p2:32:32-p3:64:64" + +@G1 = global i32 42, align 1 +@G2 = global i32 42 +@G3 = global [4 x i8] zeroinitializer, align 1 + +@A1 = alias bitcast (i8* getelementptr inbounds ([4 x i8]* @G3, i32 0, i32 2) to i32*) +@A2 = alias inttoptr (i64 and (i64 ptrtoint (i8* getelementptr inbounds ([4 x i8]* @G3, i32 0, i32 3) to i64), i64 -4) to i32*) + +define i64 @f1() { +; This cannot be constant folded because G1 is underaligned. +; CHECK-LABEL: @f1( +; CHECK: ret i64 and + ret i64 and (i64 ptrtoint (i32* @G1 to i64), i64 1) +} + +define i64 @f2() { +; The preferred alignment for G2 allows this one to foled to zero. +; CHECK-LABEL: @f2( +; CHECK: ret i64 0 + ret i64 and (i64 ptrtoint (i32* @G2 to i64), i64 1) +} + +define i64 @g1() { +; This cannot be constant folded because A1 aliases G3 which is underalaigned. +; CHECK-LABEL: @g1( +; CHECK: ret i64 and + ret i64 and (i64 ptrtoint (i32* @A1 to i64), i64 1) +} + +define i64 @g2() { +; While A2 also aliases G3 which is underaligned, the math of A2 forces a +; certain alignment allowing this to fold to zero. +; CHECK-LABEL: @g2( +; CHECK: ret i64 0 + ret i64 and (i64 ptrtoint (i32* @A2 to i64), i64 1) +} + |