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d216412b
by Ian-Woo Kim at 2026-06-16T20:25:57-04:00
Make the order of usages deterministic
It has been observed that the ordering of usages can be non-determinstic
in parallel builds. Therefore, this contribution introduces sorting of
usages based on a platform- and race-independent sorting criterion.
Resolves #26877.
Co-authored-by: Wolfgang Jeltsch <wolfgang@well-typed.com>
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8e1cc105
by Wolfgang Jeltsch at 2026-06-16T20:25:57-04:00
Change the descriptions of two existing changelog entries
The descriptions now describe the changes in a user-friendly manner, as
opposed to describing the contributions that led to these changes in a
developer-friendly manner.
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636c1c7a
by Ian Duncan at 2026-06-16T20:26:50-04:00
AArch64: use SXTH, not SXTW, for W32 signExtendReg
signExtendReg was using SXTH (sign-extend halfword, 16-bit) for
W32-to-W64 sign extension. This should be SXTW (sign-extend word,
32-bit). SXTH only sign-extends the lower 16 bits, producing wrong
results for 32-bit values whose bit 15 differs from bit 31.
Other fixes:
- At sub-W64, code gen for MO_S_Mul2 should use W32 registers for
SMULL source operands as per the ARM spec (SMULL Xd, Wn, Wm),
and not W64.
- Ensure signExtendReg uses the source width for the source operand
in SXTW/SXTH/SXTB instructions. GNU as requires sxtw Xd,Wn (not
sxtw Xd,Xn), while LLVM's integrated assembler on macOS is lenient.
- Fix overflow flag computation for `MO_S_Mul2`. The overflow bit
was exactly inverted for sub-W64 operands.
Fixes #26978 and #27047
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b734c75d
by Igor Ranieri at 2026-06-16T20:27:32-04:00
haddock: Update CONTRIBUTING with missing step, add missing test
dependency
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fa8c0c26
by Luite Stegeman at 2026-06-16T23:04:29-04:00
tag inference: don't confuse functions with their return values
inferTagRhs was mixing up taggedness for closures and return values
for function closures. We really shouldn't assign TagTuple to a
properly tagged function returning a tuple.
We fix this by keeping track of functions (TagFun) separately from
values (TagVal) and keeping track of their return value. TagFun is
also used for join points.
fixes #27005
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5c1fd991
by Sebastian Graf at 2026-06-16T23:04:30-04:00
Seed the simplifier's in-scope set for open expressions
simplifyExpr simplifies expressions typed at the GHCi prompt and the
results of Template Haskell splices. Such an expression may be open: at a
GHCi debugger breakpoint its free variables include RuntimeUnk skolems
standing for as-yet-unknown types.
The simplifier began with an in-scope set holding only the wildcard
binder, so when it instantiated the unsafeCoerce# wrapper that GHCi
builds around a result, it formed a substitution whose range mentioned a
free skolem that was not in scope. That breaks the substitution invariant
and, in a compiler built with assertions, trips substTy's sanity check.
Seed the initial in-scope set with the free variables of the expression.
For a closed expression this adds nothing.
See Note [Seed the in-scope set for open expressions].
Fixes #17833 and its duplicate #21118.