llvm-6502/test/Transforms/InstCombine/loadstore-metadata.ll
Chandler Carruth a768c4a096 [IC] Fix a bug with the instcombine canonicalizing of loads and
propagating of metadata.

We were propagating !nonnull metadata even when the newly formed load is
no longer of a pointer type. This is clearly broken and results in LLVM
failing the verifier and aborting. This patch just restricts the
propagation of !nonnull metadata to when we actually have a pointer
type.

This bug report and the initial version of this patch was provided by
Charles Davis! Many thanks for finding this!

We still need to add logic to round-trip the metadata correctly if we
combine from pointer types to integer types and then back by using range
metadata for the integer type loads. But this is the minimal and safe
version of the patch, which is important so we can backport it into 3.6.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229029 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 02:30:01 +00:00

106 lines
3.1 KiB
LLVM

; RUN: opt -instcombine -S < %s | FileCheck %s
target datalayout = "e-m:e-p:64:64:64-i64:64-f80:128-n8:16:32:64-S128"
define i32 @test_load_cast_combine_tbaa(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves TBAA.
; CHECK-LABEL: @test_load_cast_combine_tbaa(
; CHECK: load i32* %{{.*}}, !tbaa !0
entry:
%l = load float* %ptr, !tbaa !0
%c = bitcast float %l to i32
ret i32 %c
}
define i32 @test_load_cast_combine_noalias(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves no-alias metadata.
; CHECK-LABEL: @test_load_cast_combine_noalias(
; CHECK: load i32* %{{.*}}, !alias.scope !2, !noalias !1
entry:
%l = load float* %ptr, !alias.scope !2, !noalias !1
%c = bitcast float %l to i32
ret i32 %c
}
define float @test_load_cast_combine_range(i32* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) drops range metadata. It
; would be nice to preserve or update it somehow but this is hard when moving
; between types.
; CHECK-LABEL: @test_load_cast_combine_range(
; CHECK: load float* %{{.*}}
; CHECK-NOT: !range
; CHECK: ret float
entry:
%l = load i32* %ptr, !range !5
%c = bitcast i32 %l to float
ret float %c
}
define i32 @test_load_cast_combine_invariant(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves invariant metadata.
; CHECK-LABEL: @test_load_cast_combine_invariant(
; CHECK: load i32* %{{.*}}, !invariant.load !3
entry:
%l = load float* %ptr, !invariant.load !3
%c = bitcast float %l to i32
ret i32 %c
}
define i32 @test_load_cast_combine_nontemporal(float* %ptr) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves nontemporal
; metadata.
; CHECK-LABEL: @test_load_cast_combine_nontemporal(
; CHECK: load i32* %{{.*}}, !nontemporal !4
entry:
%l = load float* %ptr, !nontemporal !4
%c = bitcast float %l to i32
ret i32 %c
}
define void @test_load_cast_combine_loop(float* %src, i32* %dst, i32 %n) {
; Ensure (cast (load (...))) -> (load (cast (...))) preserves loop access
; metadata.
; CHECK-LABEL: @test_load_cast_combine_loop(
; CHECK: load i32* %{{.*}}, !llvm.mem.parallel_loop_access !1
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
%src.gep = getelementptr inbounds float* %src, i32 %i
%dst.gep = getelementptr inbounds i32* %dst, i32 %i
%l = load float* %src.gep, !llvm.mem.parallel_loop_access !1
%c = bitcast float %l to i32
store i32 %c, i32* %dst.gep
%i.next = add i32 %i, 1
%cmp = icmp slt i32 %i.next, %n
br i1 %cmp, label %loop, label %exit, !llvm.loop !1
exit:
ret void
}
define void @test_load_cast_combine_nonnull(float** %ptr) {
; We can't preserve nonnull metadata when converting a load of a pointer to
; a load of an integer.
; FIXME: We should really transform this into range metadata and vice versa.
;
; CHECK-LABEL: @test_load_cast_combine_nonnull(
; CHECK: %[[V:.*]] = load i64* %{{.*}}
; CHECK-NOT: !nonnull
; CHECK: store i64 %[[V]], i64*
entry:
%p = load float** %ptr, !nonnull !3
%gep = getelementptr float** %ptr, i32 42
store float* %p, float** %gep
ret void
}
!0 = !{ !1, !1, i64 0 }
!1 = !{ !1 }
!2 = !{ !2, !1 }
!3 = !{ }
!4 = !{ i32 1 }
!5 = !{ i32 0, i32 42 }