2b66d32f3f
llvm.ctlz.<type> intrinsic has additional i1 argument is_zero_undef, it tells whether zero as the first argument produces a defined result. MIPS clz instruction returns 32 for zero input. G_CTLZ is generated from llvm.ctlz.<type> (<type> <src>, i1 false) intrinsics, clang generates these intrinsics from __builtin_clz and __builtin_clzll. G_CTLZ_ZERO_UNDEF can also be generated from llvm.ctlz with true as second argument. It is also traditionally part of and many algorithms that are now predicated on avoiding zero-value inputs. Add narrow scalar for G_CTLZ (algorithm uses G_CTLZ_ZERO_UNDEF). Lower G_CTLZ_ZERO_UNDEF and select G_CTLZ for MIPS32. Differential Revision: https://reviews.llvm.org/D73214
25 lines
725 B
YAML
25 lines
725 B
YAML
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
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# RUN: llc -O0 -mtriple=mipsel-linux-gnu -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s -check-prefixes=MIPS32
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---
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name: ctlz_i32
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alignment: 4
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legalized: true
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regBankSelected: true
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tracksRegLiveness: true
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body: |
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bb.1.entry:
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liveins: $a0
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; MIPS32-LABEL: name: ctlz_i32
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; MIPS32: liveins: $a0
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; MIPS32: [[COPY:%[0-9]+]]:gpr32 = COPY $a0
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; MIPS32: [[CLZ:%[0-9]+]]:gpr32 = CLZ [[COPY]]
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; MIPS32: $v0 = COPY [[CLZ]]
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; MIPS32: RetRA implicit $v0
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%0:gprb(s32) = COPY $a0
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%1:gprb(s32) = G_CTLZ %0(s32)
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$v0 = COPY %1(s32)
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RetRA implicit $v0
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...
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