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authorsheaf <sam.derbyshire@gmail.com>2022-10-14 15:19:41 +0200
committerMarge Bot <ben+marge-bot@smart-cactus.org>2022-10-19 10:45:45 -0400
commit3be48877e204fca8e5d5ab984186e0d20d81f262 (patch)
treee6950cdf2df8c06454191e3e71150814e8123898
parent6d7d91817795d7ee7f45557411368a1738daa488 (diff)
downloadhaskell-3be48877e204fca8e5d5ab984186e0d20d81f262.tar.gz
Cmm Lint: relax SIMD register assignment check
As noted in #22297, SIMD vector registers can be used to store different kinds of values, e.g. xmm1 can be used both to store integer and floating point values. The Cmm type system doesn't properly account for this, so we weaken the Cmm register assignment lint check to only compare widths when comparing a vector type with its allocated vector register.
-rw-r--r--compiler/GHC/Cmm/Lint.hs18
-rw-r--r--testsuite/tests/unboxedsums/all.T5
2 files changed, 18 insertions, 5 deletions
diff --git a/compiler/GHC/Cmm/Lint.hs b/compiler/GHC/Cmm/Lint.hs
index af27e5932a..8ba4f20fa8 100644
--- a/compiler/GHC/Cmm/Lint.hs
+++ b/compiler/GHC/Cmm/Lint.hs
@@ -174,9 +174,21 @@ lintCmmMiddle node = case node of
platform <- getPlatform
erep <- lintCmmExpr expr
let reg_ty = cmmRegType platform reg
- if (erep `cmmEqType_ignoring_ptrhood` reg_ty)
- then return ()
- else cmmLintAssignErr (CmmAssign reg expr) erep reg_ty
+ unless (compat_regs erep reg_ty) $
+ cmmLintAssignErr (CmmAssign reg expr) erep reg_ty
+ where
+ compat_regs :: CmmType -> CmmType -> Bool
+ compat_regs ty1 ty2
+ -- As noted in #22297, SIMD vector registers can be used for
+ -- multiple different purposes, e.g. xmm1 can be used to hold 4 Floats,
+ -- or 4 Int32s, or 2 Word64s, ...
+ -- To allow this, we relax the check: we only ensure that the widths
+ -- match, until we can find a more robust solution.
+ | isVecType ty1
+ , isVecType ty2
+ = typeWidth ty1 == typeWidth ty2
+ | otherwise
+ = cmmEqType_ignoring_ptrhood ty1 ty2
CmmStore l r _alignment -> do
_ <- lintCmmExpr l
diff --git a/testsuite/tests/unboxedsums/all.T b/testsuite/tests/unboxedsums/all.T
index 2fb0b9ad60..acfe825080 100644
--- a/testsuite/tests/unboxedsums/all.T
+++ b/testsuite/tests/unboxedsums/all.T
@@ -36,5 +36,6 @@ test('T20858b', [extra_files(['T20858.hs'])
, ghci_script, ['T20858b.script'])
test('T20859', normal, compile, [''])
-test('T22187',[only_ways(llvm_ways), expect_broken(22296)],compile,[''])
-test('T22187_run',[only_ways(llvm_ways), expect_broken(22296)],compile_and_run,[''])
+test('T22187',[only_ways(llvm_ways)],compile,[''])
+test('T22187_run',[only_ways(llvm_ways)],compile_and_run,[''])
+