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x64: fix miscompilation of select.i128 (#4017)

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Issue #3963 identified a miscompilation with select in which the second
in the pair of `CMOV`s (one pair per `i128` register) used the wrong
flag. This change fixes the error in the x64 ISLE helper function
emitting these `CMOV` instructions.
This commit is contained in:
Andrew Brown
2022-04-12 09:56:57 -07:00
committed by GitHub
parent 54aa720506
commit 7a55779c6b
5 changed files with 42 additions and 6 deletions
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11
cranelift/filetests/filetests/runtests/i128-select.clif
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@@ -10,6 +10,15 @@ block0(v0: b1, v1: i128, v2: i128):
}
; run: %i128_select(true, 0, 1) == 0
; run: %i128_select(false, 0, 1) == 1
; run: %i128_select(true, 0x00000000_00000000_DECAFFFF_C0FFEEEE, 0xFFFFFFFF_FFFFFFFF_C0FFEEEE_DECAFFFF) == 0x00000000_00000000_DECAFFFF_C0FFEEEE
; run: %i128_select(false, 0x00000000_00000000_DECAFFFF_C0FFEEEE, 0xFFFFFFFF_FFFFFFFF_C0FFEEEE_DECAFFFF) == 0xFFFFFFFF_FFFFFFFF_C0FFEEEE_DECAFFFF
;; Test for issue: https://github.com/bytecodealliance/wasmtime/issues/3963.
function %i128_fcmp_eq_select(f32, i128, i128) -> i128 {
block0(v0: f32, v1: i128, v2: i128):
v3 = fcmp eq v0, v0
v4 = select.i128 v3, v1, v2
return v4
}
; run: %i128_fcmp_eq_select(0x42.42, 1, 0) == 1
; run: %i128_fcmp_eq_select(NaN, 1, 0) == 0