maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/test/CodeGen/PowerPC/fp64-to-int16.ll

22 lines
590 B
LLVM
Raw Normal View History

[Legalizer] Fix fp-to-uint to fp-tosint promotion assertion. Summary: When promoting fp-to-uint16 to fp-to-sint32, the result is actually zero extended. For example, given double 65534.0, without legalization: fp-to-uint16: 65534.0 -> 0xfffe With the legalization: fp-to-sint32: 65534.0 -> 0x0000fffe Without this patch, legalization wrongly emits a signed extend assertion, which is consumed by later icmp instruction, and cause miscompile. Note that the floating point value must be in [0, 65535), otherwise the behavior is undefined. This patch reverts r279223 behavior and adds more tests and documentations. In PR29041's context, James Molloy mentioned that: We don't need to mask because conversion from float->uint8_t is undefined if the integer part of the float value is not representable in uint8_t. Therefore we can assume this doesn't happen! which is totally true and good, because fptoui is documented clearly to have undefined behavior when overflow/underflow happens. We should take the advantage of this behavior so that we can save unnecessary mask instructions. Reviewers: jmolloy, nadav, echristo, kbarton Subscribers: mehdi_amini, nemanjai, llvm-commits Differential Revision: https://reviews.llvm.org/D28284 llvm-svn: 291015
2017-01-05 06:11:42 +08:00
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -O0 < %s | FileCheck %s
target triple = "powerpc64le--linux-gnu"
define i1 @Test(double %a) {
; CHECK-LABEL: Test:
[CodeGen] Unify MBB reference format in both MIR and debug output As part of the unification of the debug format and the MIR format, print MBB references as '%bb.5'. The MIR printer prints the IR name of a MBB only for block definitions. * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g' * find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g' * grep -nr 'BB#' and fix Differential Revision: https://reviews.llvm.org/D40422 llvm-svn: 319665
2017-12-05 01:18:51 +08:00
; CHECK: # %bb.0: # %entry
[Legalizer] Fix fp-to-uint to fp-tosint promotion assertion. Summary: When promoting fp-to-uint16 to fp-to-sint32, the result is actually zero extended. For example, given double 65534.0, without legalization: fp-to-uint16: 65534.0 -> 0xfffe With the legalization: fp-to-sint32: 65534.0 -> 0x0000fffe Without this patch, legalization wrongly emits a signed extend assertion, which is consumed by later icmp instruction, and cause miscompile. Note that the floating point value must be in [0, 65535), otherwise the behavior is undefined. This patch reverts r279223 behavior and adds more tests and documentations. In PR29041's context, James Molloy mentioned that: We don't need to mask because conversion from float->uint8_t is undefined if the integer part of the float value is not representable in uint8_t. Therefore we can assume this doesn't happen! which is totally true and good, because fptoui is documented clearly to have undefined behavior when overflow/underflow happens. We should take the advantage of this behavior so that we can save unnecessary mask instructions. Reviewers: jmolloy, nadav, echristo, kbarton Subscribers: mehdi_amini, nemanjai, llvm-commits Differential Revision: https://reviews.llvm.org/D28284 llvm-svn: 291015
2017-01-05 06:11:42 +08:00
; CHECK-NEXT: xscvdpsxws 1, 1
; CHECK-NEXT: mfvsrwz 3, 1
; CHECK-NEXT: xori 3, 3, 65534
; CHECK-NEXT: cntlzw 3, 3
; CHECK-NEXT: srwi 3, 3, 5
Followup on Proposal to move MIR physical register namespace to '$' sigil. Discussed here: http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html In preparation for adding support for named vregs we are changing the sigil for physical registers in MIR to '$' from '%'. This will prevent name clashes of named physical register with named vregs. llvm-svn: 323922
2018-02-01 06:04:26 +08:00
; CHECK-NEXT: # implicit-def: $x4
[Legalizer] Fix fp-to-uint to fp-tosint promotion assertion. Summary: When promoting fp-to-uint16 to fp-to-sint32, the result is actually zero extended. For example, given double 65534.0, without legalization: fp-to-uint16: 65534.0 -> 0xfffe With the legalization: fp-to-sint32: 65534.0 -> 0x0000fffe Without this patch, legalization wrongly emits a signed extend assertion, which is consumed by later icmp instruction, and cause miscompile. Note that the floating point value must be in [0, 65535), otherwise the behavior is undefined. This patch reverts r279223 behavior and adds more tests and documentations. In PR29041's context, James Molloy mentioned that: We don't need to mask because conversion from float->uint8_t is undefined if the integer part of the float value is not representable in uint8_t. Therefore we can assume this doesn't happen! which is totally true and good, because fptoui is documented clearly to have undefined behavior when overflow/underflow happens. We should take the advantage of this behavior so that we can save unnecessary mask instructions. Reviewers: jmolloy, nadav, echristo, kbarton Subscribers: mehdi_amini, nemanjai, llvm-commits Differential Revision: https://reviews.llvm.org/D28284 llvm-svn: 291015
2017-01-05 06:11:42 +08:00
; CHECK-NEXT: mr 4, 3
; CHECK-NEXT: mr 3, 4
; CHECK-NEXT: blr
entry:
%conv = fptoui double %a to i16
%cmp = icmp eq i16 %conv, -2
ret i1 %cmp
}