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llvm-6502/test/CodeGen/ARM/2013-05-13-AAPCS-byval-padding.ll

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PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
;PR15293: ARM codegen ice - expected larger existing stack allocation
;RUN: llc -mtriple=arm-linux-gnueabihf < %s | FileCheck %s
%struct.S227 = type { [49 x i32], i32 }
define void @check227(
ARM: simplify and extend byval handling The main issue being fixed here is that APCS targets handling a "byval align N" parameter with N > 4 were miscounting what objects were where on the stack, leading to FrameLowering setting the frame pointer incorrectly and clobbering the stack. But byval handling had grown over many years, and had multiple layers of cruft trying to compensate for each other and calculate padding correctly. This only really needs to be done once, in the HandleByVal function. Elsewhere should just do what it's told by that call. I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits byvals with the correct C ABI alignment), which simplified HandleByVal. rdar://20095672 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00
i32 %b,
PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
%struct.S227* byval nocapture %arg0,
%struct.S227* %arg1) {
; b --> R0
; arg0 --> [R1, R2, R3, SP+0 .. SP+188)
; arg1 --> SP+188
entry:
ARM: simplify and extend byval handling The main issue being fixed here is that APCS targets handling a "byval align N" parameter with N > 4 were miscounting what objects were where on the stack, leading to FrameLowering setting the frame pointer incorrectly and clobbering the stack. But byval handling had grown over many years, and had multiple layers of cruft trying to compensate for each other and calculate padding correctly. This only really needs to be done once, in the HandleByVal function. Elsewhere should just do what it's told by that call. I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits byvals with the correct C ABI alignment), which simplified HandleByVal. rdar://20095672 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00
;CHECK: sub sp, sp, #12
PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
;CHECK: push {r11, lr}
ARM: simplify and extend byval handling The main issue being fixed here is that APCS targets handling a "byval align N" parameter with N > 4 were miscounting what objects were where on the stack, leading to FrameLowering setting the frame pointer incorrectly and clobbering the stack. But byval handling had grown over many years, and had multiple layers of cruft trying to compensate for each other and calculate padding correctly. This only really needs to be done once, in the HandleByVal function. Elsewhere should just do what it's told by that call. I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits byvals with the correct C ABI alignment), which simplified HandleByVal. rdar://20095672 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00
;CHECK: sub sp, sp, #4
PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
;CHECK: add r0, sp, #12
;CHECK: stm r0, {r1, r2, r3}
;CHECK: ldr r0, [sp, #212]
;CHECK: bl useInt
ARM: simplify and extend byval handling The main issue being fixed here is that APCS targets handling a "byval align N" parameter with N > 4 were miscounting what objects were where on the stack, leading to FrameLowering setting the frame pointer incorrectly and clobbering the stack. But byval handling had grown over many years, and had multiple layers of cruft trying to compensate for each other and calculate padding correctly. This only really needs to be done once, in the HandleByVal function. Elsewhere should just do what it's told by that call. I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits byvals with the correct C ABI alignment), which simplified HandleByVal. rdar://20095672 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00
;CHECK: add sp, sp, #4
PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
;CHECK: pop {r11, lr}
ARM: simplify and extend byval handling The main issue being fixed here is that APCS targets handling a "byval align N" parameter with N > 4 were miscounting what objects were where on the stack, leading to FrameLowering setting the frame pointer incorrectly and clobbering the stack. But byval handling had grown over many years, and had multiple layers of cruft trying to compensate for each other and calculate padding correctly. This only really needs to be done once, in the HandleByVal function. Elsewhere should just do what it's told by that call. I also stripped out unnecessary APCS/AAPCS distinctions (now that Clang emits byvals with the correct C ABI alignment), which simplified HandleByVal. rdar://20095672 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231959 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-11 18:54:22 +00:00
;CHECK: add sp, sp, #12
PR15868 fix. Introduction: In case when stack alignment is 8 and GPRs parameter part size is not N*8: we add padding to GPRs part, so part's last byte must be recovered at address K*8-1. We need to do it, since remained (stack) part of parameter starts from address K*8, and we need to "attach" "GPRs head" without gaps to it: Stack: |---- 8 bytes block ----| |---- 8 bytes block ----| |---- 8 bytes... [ [padding] [GPRs head] ] [ ------ Tail passed via stack ------ ... FIX: Note, once we added padding we need to correct *all* Arg offsets that are going after padded one. That's why we need this fix: Arg offsets were never corrected before this patch. See new test-cases included in patch. We also don't need to insert padding for byval parameters that are stored in GPRs only. We need pad only last byval parameter and only in case it outsides GPRs and stack alignment = 8. Though, stack area, allocated for recovered byval params, must satisfy "Size mod 8 = 0" restriction. This patch reduces stack usage for some cases: We can reduce ArgRegsSaveArea since inner N*4 bytes sized byval params my be "packed" with alignment 4 in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182237 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-20 08:01:34 +00:00
%0 = ptrtoint %struct.S227* %arg1 to i32
tail call void @useInt(i32 %0)
ret void
}
declare void @useInt(i32)
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