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https://github.com/c64scene-ar/llvm-6502.git
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a29c13086a
inform the optimizers that the result must be zero/ sign extended from the smaller type. For example, if a fp to unsigned i16 is promoted to fp to i32, then we are allowed to assume that the extra 16 bits are zero (because the result of fp to i16 is undefined if the result does not fit in an i16). This is quite aggressive, but should help the optimizers produce better code. This requires correcting a test which thought that fp_to_uint is some kind of truncation, which it is not: in the testcase (which does fp to i1), either the fp value converts to 0 or 1 or the result is undefined, which is quite different to truncation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58991 91177308-0d34-0410-b5e6-96231b3b80d8
52 lines
1.2 KiB
LLVM
52 lines
1.2 KiB
LLVM
; An integer truncation to i1 should be done with an and instruction to make
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; sure only the LSBit survives. Test that this is the case both for a returned
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; value and as the operand of a branch.
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; RUN: llvm-as < %s | llc -march=x86 | grep {\\(and\\)\\|\\(test.*\\\$1\\)} | \
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; RUN: count 5
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define i1 @test1(i32 %X) zeroext {
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%Y = trunc i32 %X to i1
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ret i1 %Y
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}
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define i1 @test2(i32 %val, i32 %mask) {
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entry:
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%shifted = ashr i32 %val, %mask
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%anded = and i32 %shifted, 1
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%trunced = trunc i32 %anded to i1
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br i1 %trunced, label %ret_true, label %ret_false
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ret_true:
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ret i1 true
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ret_false:
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ret i1 false
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}
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define i32 @test3(i8* %ptr) {
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%val = load i8* %ptr
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%tmp = trunc i8 %val to i1
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br i1 %tmp, label %cond_true, label %cond_false
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cond_true:
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ret i32 21
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cond_false:
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ret i32 42
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}
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define i32 @test4(i8* %ptr) {
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%tmp = ptrtoint i8* %ptr to i1
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br i1 %tmp, label %cond_true, label %cond_false
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cond_true:
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ret i32 21
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cond_false:
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ret i32 42
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}
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define i32 @test6(double %d) {
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%tmp = fptosi double %d to i1
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br i1 %tmp, label %cond_true, label %cond_false
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cond_true:
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ret i32 21
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cond_false:
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ret i32 42
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}
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