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llvm-project/llvm/test/CodeGen/ARM/clz.ll

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[ARM] Lower llvm.ctlz.i32 to a libcall when clz is not available. The inline sequence is very long (about 70 bytes on Thumb1), so it's not really a good idea to inline it, especially when optimizing for size. Differential Revision: https://reviews.llvm.org/D47917 llvm-svn: 340458
2018-08-23 05:47:14 +08:00
; RUN: llc -mtriple=arm-eabi -mattr=+v5t %s -o - | FileCheck %s -check-prefixes=CHECK,INLINE
; RUN: llc -mtriple=arm-eabi %s -o - | FileCheck %s -check-prefixes=CHECK,LIBCALL
ARM test cases contributed by Apple. llvm-svn: 33354
2007-01-19 17:20:23 +08:00
Manually upgrade the test suite to specify the flag to cttz and ctlz. I followed three heuristics for deciding whether to set 'true' or 'false': - Everything target independent got 'true' as that is the expected common output of the GCC builtins. - If the target arch only has one way of implementing this operation, set the flag in the way that exercises the most of codegen. For most architectures this is also the likely path from a GCC builtin, with 'true' being set. It will (eventually) require lowering away that difference, and then lowering to the architecture's operation. - Otherwise, set the flag differently dependending on which target operation should be tested. Let me know if anyone has any issue with this pattern or would like specific tests of another form. This should allow the x86 codegen to just iteratively improve as I teach the backend how to differentiate between the two forms, and everything else should remain exactly the same. llvm-svn: 146370
2011-12-12 19:59:10 +08:00
declare i32 @llvm.ctlz.i32(i32, i1)
ARM test cases contributed by Apple. llvm-svn: 33354
2007-01-19 17:20:23 +08:00
Remove llvm-upgrade. llvm-svn: 47238
2008-02-18 04:02:20 +08:00
define i32 @test(i32 %x) {
[ARM] Lower llvm.ctlz.i32 to a libcall when clz is not available. The inline sequence is very long (about 70 bytes on Thumb1), so it's not really a good idea to inline it, especially when optimizing for size. Differential Revision: https://reviews.llvm.org/D47917 llvm-svn: 340458
2018-08-23 05:47:14 +08:00
; CHECK-LABEL: test
; INLINE: clz r0, r0
; LIBCALL: b __clzsi2
Manually upgrade the test suite to specify the flag to cttz and ctlz. I followed three heuristics for deciding whether to set 'true' or 'false': - Everything target independent got 'true' as that is the expected common output of the GCC builtins. - If the target arch only has one way of implementing this operation, set the flag in the way that exercises the most of codegen. For most architectures this is also the likely path from a GCC builtin, with 'true' being set. It will (eventually) require lowering away that difference, and then lowering to the architecture's operation. - Otherwise, set the flag differently dependending on which target operation should be tested. Let me know if anyone has any issue with this pattern or would like specific tests of another form. This should allow the x86 codegen to just iteratively improve as I teach the backend how to differentiate between the two forms, and everything else should remain exactly the same. llvm-svn: 146370
2011-12-12 19:59:10 +08:00
%tmp.1 = call i32 @llvm.ctlz.i32( i32 %x, i1 true )
Remove llvm-upgrade. llvm-svn: 47238
2008-02-18 04:02:20 +08:00
ret i32 %tmp.1
ARM test cases contributed by Apple. llvm-svn: 33354
2007-01-19 17:20:23 +08:00
}