Fix PR1749 and InstCombine/2007-10-28-EmptyField.ll by handling

zero-length fields better.

llvm-svn: 43427
This commit is contained in:
Chris Lattner 2007-10-29 02:40:02 +00:00
parent 891066cfff
commit 7e3a8a7604
2 changed files with 31 additions and 1 deletions

View File

@ -83,9 +83,15 @@ unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
assert(SI != &MemberOffsets[0] && "Offset not in structure type!");
--SI;
assert(*SI <= Offset && "upper_bound didn't work");
assert((SI == &MemberOffsets[0] || *(SI-1) < Offset) &&
assert((SI == &MemberOffsets[0] || *(SI-1) <= Offset) &&
(SI+1 == &MemberOffsets[NumElements] || *(SI+1) > Offset) &&
"Upper bound didn't work!");
// Multiple fields can have the same offset if any of them are zero sized.
// For example, in { i32, [0 x i32], i32 }, searching for offset 4 will stop
// at the i32 element, because it is the last element at that offset. This is
// the right one to return, because anything after it will have a higher
// offset, implying that this element is non-empty.
return SI-&MemberOffsets[0];
}

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@ -0,0 +1,24 @@
; RUN: llvm-as < %s | opt -instcombine -disable-output
; PR1749
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
target triple = "x86_64-unknown-linux-gnu"
%struct.__large_struct = type { [100 x i64] }
%struct.compat_siginfo = type { i32, i32, i32, { [29 x i32] } }
%struct.siginfo_t = type { i32, i32, i32, { { i32, i32, [0 x i8], %struct.sigval_t, i32 }, [88 x i8] } }
%struct.sigval_t = type { i8* }
define i32 @copy_siginfo_to_user32(%struct.compat_siginfo* %to, %struct.siginfo_t* %from) {
entry:
%from_addr = alloca %struct.siginfo_t* ; <%struct.siginfo_t**> [#uses=1]
%tmp344 = load %struct.siginfo_t** %from_addr, align 8 ; <%struct.siginfo_t*> [#uses=1]
%tmp345 = getelementptr %struct.siginfo_t* %tmp344, i32 0, i32 3 ; <{ { i32, i32, [0 x i8], %struct.sigval_t, i32 }, [88 x i8] }*> [#uses=1]
%tmp346 = getelementptr { { i32, i32, [0 x i8], %struct.sigval_t, i32 }, [88 x i8] }* %tmp345, i32 0, i32 0 ; <{ i32, i32, [0 x i8], %struct.sigval_t, i32 }*> [#uses=1]
%tmp346347 = bitcast { i32, i32, [0 x i8], %struct.sigval_t, i32 }* %tmp346 to { i32, i32, %struct.sigval_t }* ; <{ i32, i32, %struct.sigval_t }*> [#uses=1]
%tmp348 = getelementptr { i32, i32, %struct.sigval_t }* %tmp346347, i32 0, i32 2 ; <%struct.sigval_t*> [#uses=1]
%tmp349 = getelementptr %struct.sigval_t* %tmp348, i32 0, i32 0 ; <i8**> [#uses=1]
%tmp349350 = bitcast i8** %tmp349 to i32* ; <i32*> [#uses=1]
%tmp351 = load i32* %tmp349350, align 8 ; <i32> [#uses=1]
%tmp360 = call i32 asm sideeffect "1:\09movl ${1:k},$2\0A2:\0A.section .fixup,\22ax\22\0A3:\09mov $3,$0\0A\09jmp 2b\0A.previous\0A.section __ex_table,\22a\22\0A\09.align 8\0A\09.quad 1b,3b\0A.previous", "=r,ir,*m,i,0,~{dirflag},~{fpsr},~{flags}"( i32 %tmp351, %struct.__large_struct* null, i32 -14, i32 0 ) ; <i32> [#uses=0]
unreachable
}