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llvm-6502/test/Transforms/SROA/big-endian.ll

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Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
; 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
Fix typo in test-case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170015 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 20:29:06 +00:00
; CHECK-NOT: store
; CHECK-NOT: load
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; 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]]
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%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
Fix typo in test-case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170015 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 20:29:06 +00:00
; CHECK-NOT: store
; CHECK-NOT: load
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK: %[[shift0:.*]] = lshr i24 %[[insert0]], 16
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
; CHECK-NEXT: %[[trunc0:.*]] = trunc i24 %[[shift0]] to i8
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK-NEXT: %[[shift1:.*]] = lshr i24 %[[insert0]], 8
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
; CHECK-NEXT: %[[trunc1:.*]] = trunc i24 %[[shift1]] to i8
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK-NEXT: %[[trunc2:.*]] = trunc i24 %[[insert0]] to i8
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%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
Fix typo in test-case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170015 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 20:29:06 +00:00
; CHECK-NOT: store
; CHECK-NOT: load
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%a0i16ptr = bitcast i8* %a0ptr to i16*
store i16 1, i16* %a0i16ptr
store i8 1, i8* %a2ptr
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
; CHECK: %[[mask1:.*]] = and i40 undef, 4294967295
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK-NEXT: %[[insert1:.*]] = or i40 %[[mask1]], 4294967296
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%a3i24ptr = bitcast i8* %a3ptr to i24*
store i24 1, i24* %a3i24ptr
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK-NEXT: %[[mask2:.*]] = and i40 %[[insert1]], -4294967041
; CHECK-NEXT: %[[insert2:.*]] = or i40 %[[mask2]], 256
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%a2i40ptr = bitcast i8* %a2ptr to i40*
store i40 1, i40* %a2i40ptr
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; CHECK-NEXT: %[[ext3:.*]] = zext i40 1 to i56
; CHECK-NEXT: %[[mask3:.*]] = and i56 undef, -1099511627776
; CHECK-NEXT: %[[insert3:.*]] = or i56 %[[mask3]], %[[ext3]]
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
Fix typo in test-case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170015 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-12 20:29:06 +00:00
; CHECK-NOT: store
; CHECK-NOT: load
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
%aiptr = bitcast [7 x i8]* %a to i56*
%ai = load i56* %aiptr
%ret = zext i56 %ai to i64
ret i64 %ret
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
; CHECK-NEXT: %[[ext4:.*]] = zext i16 1 to i56
Teach SROA how to split whole-alloca integer loads and stores into smaller integer loads and stores. The high-level motivation is that the frontend sometimes generates a single whole-alloca integer load or store during ABI lowering of splittable allocas. We need to be able to break this apart in order to see the underlying elements and properly promote them to SSA values. The hope is that this fixes some performance regressions on x86-32 with the new SROA pass. Unfortunately, this causes quite a bit of churn in the test cases, and bloats some IR that comes out. When we see an alloca that consists soley of bits and bytes being extracted and re-inserted, we now do some splitting first, before building widened integer "bucket of bits" representations. These are always well folded by instcombine however, so this shouldn't actually result in missed opportunities. If this splitting of all-integer allocas does cause problems (perhaps due to smaller SSA values going into the RA), we could potentially go to some extreme measures to only do this integer splitting trick when there are non-integer component accesses of an alloca, but discovering this is quite expensive: it adds yet another complete walk of the recursive use tree of the alloca. Either way, I will be watching build bots and LNT bots to see what fallout there is here. If anyone gets x86-32 numbers before & after this change, I would be very interested. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166662 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25 04:37:07 +00:00
; 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
Teach the integer-promotion rewrite strategy to be endianness aware. Sorry for this being broken so long. =/ As part of this, switch all of the existing tests to be Little Endian, which is the behavior I was asserting in them anyways! Add in a new big-endian test that checks the interesting behavior there. Another part of this is to tighten the rules abotu when we perform the full-integer promotion. This logic now rejects cases where there fully promoted integer is a non-multiple-of-8 bitwidth or cases where the loads or stores touch bits which are in the allocated space of the alloca but are not loaded or stored when accessing the integer. Sadly, these aren't really observable today as the rest of the pass will already ensure the invariants hold. However, the latter situation is likely to become a potential concern in the future. Thanks to Benjamin and Duncan for early review of this patch. I'm still looking into whether there are further endianness issues, please let me know if anyone sees BE failures persisting past this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
; CHECK-NEXT: ret i64 %[[ret]]
}
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