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| author | Herbert Valerio Riedel <hvr@gnu.org> | 2014-08-11 18:56:57 +0200 |
|---|---|---|
| committer | Herbert Valerio Riedel <hvr@gnu.org> | 2014-08-14 11:34:23 +0200 |
| commit | e0c1767d0ea8d12e0a4badf43682a08784e379c6 (patch) | |
| tree | 6662fe33cd7e803253458f91307b1b5826e30b0f /compiler/llvmGen/LlvmCodeGen | |
| parent | 6b5ea617dcd162e682886d5843df51a2866218d3 (diff) | |
| download | haskell-e0c1767d0ea8d12e0a4badf43682a08784e379c6.tar.gz | |
Implement new CLZ and CTZ primops (re #9340)
This implements the new primops
clz#, clz32#, clz64#,
ctz#, ctz32#, ctz64#
which provide efficient implementations of the popular
count-leading-zero and count-trailing-zero respectively
(see testcase for a pure Haskell reference implementation).
On x86, NCG as well as LLVM generates code based on the BSF/BSR
instructions (which need extra logic to make the 0-case well-defined).
Test Plan: validate and succesful tests on i686 and amd64
Reviewers: rwbarton, simonmar, ezyang, austin
Subscribers: simonmar, relrod, ezyang, carter
Differential Revision: https://phabricator.haskell.org/D144
GHC Trac Issues: #9340
Diffstat (limited to 'compiler/llvmGen/LlvmCodeGen')
| -rw-r--r-- | compiler/llvmGen/LlvmCodeGen/CodeGen.hs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs index 4a56600937..2673eed6b8 100644 --- a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs +++ b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs @@ -224,9 +224,14 @@ genCall t@(PrimTarget (MO_Prefetch_Data localityInt)) [] args return (stmts, top1 ++ top2) | otherwise = panic $ "prefetch locality level integer must be between 0 and 3, given: " ++ (show localityInt) --- Handle PopCnt and BSwap that need to only convert arg and return types +-- Handle PopCnt, Clz, Ctz, and BSwap that need to only convert arg +-- and return types genCall t@(PrimTarget (MO_PopCnt w)) dsts args = genCallSimpleCast w t dsts args +genCall t@(PrimTarget (MO_Clz w)) dsts args = + genCallSimpleCast w t dsts args +genCall t@(PrimTarget (MO_Ctz w)) dsts args = + genCallSimpleCast w t dsts args genCall t@(PrimTarget (MO_BSwap w)) dsts args = genCallSimpleCast w t dsts args @@ -558,6 +563,8 @@ cmmPrimOpFunctions mop = do (MO_PopCnt w) -> fsLit $ "llvm.ctpop." ++ showSDoc dflags (ppr $ widthToLlvmInt w) (MO_BSwap w) -> fsLit $ "llvm.bswap." ++ showSDoc dflags (ppr $ widthToLlvmInt w) + (MO_Clz w) -> fsLit $ "llvm.ctlz." ++ showSDoc dflags (ppr $ widthToLlvmInt w) + (MO_Ctz w) -> fsLit $ "llvm.cttz." ++ showSDoc dflags (ppr $ widthToLlvmInt w) (MO_Prefetch_Data _ )-> fsLit "llvm.prefetch" |