llvm-6502/test/Transforms/SROA/big-endian.ll
Chandler Carruth 3d9afa8e97 Fix PR14548: SROA was crashing on a mixture of i1 and i8 loads and stores.
When SROA was evaluating a mixture of i1 and i8 loads and stores, in
just a particular case, it would tickle a latent bug where we compared
bits to bytes rather than bits to bits. As a consequence of the latent
bug, we would allow integers through which were not byte-size multiples,
a situation the later rewriting code was never intended to handle.

In release builds this could trigger all manner of oddities, but the
reported issue in PR14548 was forming invalid bitcast instructions.

The only downside of this fix is that it makes it more clear that SROA
in its current form is not capable of handling mixed i1 and i8 loads and
stores. Sometimes with the previous code this would work by luck, but
usually it would crash, so I'm not terribly worried. I'll watch the LNT
numbers just to be sure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169719 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-10 00:54:45 +00:00

115 lines
3.8 KiB
LLVM

; RUN: opt < %s -sroa -S | FileCheck %s
; RUN: opt < %s -sroa -force-ssa-updater -S | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n8:16:32:64"
define i8 @test1() {
; We fully promote these to the i24 load or store size, resulting in just masks
; and other operations that instcombine will fold, but no alloca. Note this is
; the same as test12 in basictest.ll, but here we assert big-endian byte
; ordering.
;
; CHECK: @test1
entry:
%a = alloca [3 x i8]
%b = alloca [3 x i8]
; CHECK-NOT: alloca
%a0ptr = getelementptr [3 x i8]* %a, i64 0, i32 0
store i8 0, i8* %a0ptr
%a1ptr = getelementptr [3 x i8]* %a, i64 0, i32 1
store i8 0, i8* %a1ptr
%a2ptr = getelementptr [3 x i8]* %a, i64 0, i32 2
store i8 0, i8* %a2ptr
%aiptr = bitcast [3 x i8]* %a to i24*
%ai = load i24* %aiptr
; CHCEK-NOT: store
; CHCEK-NOT: load
; CHECK: %[[ext2:.*]] = zext i8 0 to i24
; CHECK-NEXT: %[[mask2:.*]] = and i24 undef, -256
; CHECK-NEXT: %[[insert2:.*]] = or i24 %[[mask2]], %[[ext2]]
; CHECK-NEXT: %[[ext1:.*]] = zext i8 0 to i24
; CHECK-NEXT: %[[shift1:.*]] = shl i24 %[[ext1]], 8
; CHECK-NEXT: %[[mask1:.*]] = and i24 %[[insert2]], -65281
; CHECK-NEXT: %[[insert1:.*]] = or i24 %[[mask1]], %[[shift1]]
; CHECK-NEXT: %[[ext0:.*]] = zext i8 0 to i24
; CHECK-NEXT: %[[shift0:.*]] = shl i24 %[[ext0]], 16
; CHECK-NEXT: %[[mask0:.*]] = and i24 %[[insert1]], 65535
; CHECK-NEXT: %[[insert0:.*]] = or i24 %[[mask0]], %[[shift0]]
%biptr = bitcast [3 x i8]* %b to i24*
store i24 %ai, i24* %biptr
%b0ptr = getelementptr [3 x i8]* %b, i64 0, i32 0
%b0 = load i8* %b0ptr
%b1ptr = getelementptr [3 x i8]* %b, i64 0, i32 1
%b1 = load i8* %b1ptr
%b2ptr = getelementptr [3 x i8]* %b, i64 0, i32 2
%b2 = load i8* %b2ptr
; CHCEK-NOT: store
; CHCEK-NOT: load
; CHECK: %[[shift0:.*]] = lshr i24 %[[insert0]], 16
; CHECK-NEXT: %[[trunc0:.*]] = trunc i24 %[[shift0]] to i8
; CHECK-NEXT: %[[shift1:.*]] = lshr i24 %[[insert0]], 8
; CHECK-NEXT: %[[trunc1:.*]] = trunc i24 %[[shift1]] to i8
; CHECK-NEXT: %[[trunc2:.*]] = trunc i24 %[[insert0]] to i8
%bsum0 = add i8 %b0, %b1
%bsum1 = add i8 %bsum0, %b2
ret i8 %bsum1
; CHECK: %[[sum0:.*]] = add i8 %[[trunc0]], %[[trunc1]]
; CHECK-NEXT: %[[sum1:.*]] = add i8 %[[sum0]], %[[trunc2]]
; CHECK-NEXT: ret i8 %[[sum1]]
}
define i64 @test2() {
; Test for various mixed sizes of integer loads and stores all getting
; promoted.
;
; CHECK: @test2
entry:
%a = alloca [7 x i8]
; CHECK-NOT: alloca
%a0ptr = getelementptr [7 x i8]* %a, i64 0, i32 0
%a1ptr = getelementptr [7 x i8]* %a, i64 0, i32 1
%a2ptr = getelementptr [7 x i8]* %a, i64 0, i32 2
%a3ptr = getelementptr [7 x i8]* %a, i64 0, i32 3
; CHCEK-NOT: store
; CHCEK-NOT: load
%a0i16ptr = bitcast i8* %a0ptr to i16*
store i16 1, i16* %a0i16ptr
store i8 1, i8* %a2ptr
; CHECK: %[[mask1:.*]] = and i40 undef, 4294967295
; CHECK-NEXT: %[[insert1:.*]] = or i40 %[[mask1]], 4294967296
%a3i24ptr = bitcast i8* %a3ptr to i24*
store i24 1, i24* %a3i24ptr
; CHECK-NEXT: %[[mask2:.*]] = and i40 %[[insert1]], -4294967041
; CHECK-NEXT: %[[insert2:.*]] = or i40 %[[mask2]], 256
%a2i40ptr = bitcast i8* %a2ptr to i40*
store i40 1, i40* %a2i40ptr
; CHECK-NEXT: %[[ext3:.*]] = zext i40 1 to i56
; CHECK-NEXT: %[[mask3:.*]] = and i56 undef, -1099511627776
; CHECK-NEXT: %[[insert3:.*]] = or i56 %[[mask3]], %[[ext3]]
; CHCEK-NOT: store
; CHCEK-NOT: load
%aiptr = bitcast [7 x i8]* %a to i56*
%ai = load i56* %aiptr
%ret = zext i56 %ai to i64
ret i64 %ret
; CHECK-NEXT: %[[ext4:.*]] = zext i16 1 to i56
; CHECK-NEXT: %[[shift4:.*]] = shl i56 %[[ext4]], 40
; CHECK-NEXT: %[[mask4:.*]] = and i56 %[[insert3]], 1099511627775
; CHECK-NEXT: %[[insert4:.*]] = or i56 %[[mask4]], %[[shift4]]
; CHECK-NEXT: %[[ret:.*]] = zext i56 %[[insert4]] to i64
; CHECK-NEXT: ret i64 %[[ret]]
}