llvm-6502/test/Transforms/InstCombine/2007-12-12-GEPScale.ll
Wojciech Matyjewicz ed2232502e 1. "Upgrage" comments.
2. Using zero-extended value of Scale and unsigned division is safe provided
   that Scale doesn't have the sign bit set.
   Previously these 2 instructions:
        %p = bitcast [100 x {i8,i8,i8}]* %x to i8*
        %q = getelementptr i8* %p, i32 -4
   were combined into:
        %q = getelementptr [100 x { i8, i8, i8 }]* %x, i32 0,
               i32 1431655764, i32 0
   what was incorrect.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44936 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-12 15:21:32 +00:00

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377 B
LLVM

; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep 1431655764
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
define i8* @foo([100 x {i8,i8,i8}]* %x) {
entry:
%p = bitcast [100 x {i8,i8,i8}]* %x to i8*
%q = getelementptr i8* %p, i32 -4
ret i8* %q
}