llvm-6502/test/Transforms/InstCombine/loadstore-metadata.ll
Chandler Carruth 63276ccdbd Do a better and more complete job of preserving metadata when combining
loads.

This handles many more cases than just the AA metadata, some of them
suggested by Hal in his review of the AA metadata handling patch. I've
tried to test this behavior where tractable to do so.

I'll point out that I have specifically *not* included a test for
debuginfo because it was going to require 2 or 3 times as much work to
craft some input which would survive the "helpful" stripping of debug
info metadata that doesn't match the desired schema. This is another
good example of why the current state of write-ability for our debug
info metadata is unacceptable. I spent over 30 minutes trying to conjure
some test case that would survive, even copying from other debug info
tests, but it always failed to survive with no explanation of why or how
I might fix it. =[

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220165 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-19 10:46:46 +00:00

87 lines
2.7 KiB
LLVM

; RUN: opt -instcombine -S < %s | FileCheck %s
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
}
!0 = metadata !{ metadata !1, metadata !1, i64 0 }
!1 = metadata !{ metadata !1 }
!2 = metadata !{ metadata !2, metadata !1 }
!3 = metadata !{ }
!4 = metadata !{ i32 1 }
!5 = metadata !{ i32 0, i32 42 }