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| author | Paul E. Murphy <murp@ibm.com> | 2023-07-11 09:07:43 -0500 |
|---|---|---|
| committer | Paul Murphy <murp@ibm.com> | 2023-07-12 16:34:02 +0000 |
| commit | 5e4000ad7ff153d90e77c97d7f29d3a2fa6c7de0 (patch) | |
| tree | 878d8a3ba1b023d500fa8042ae877e70026d277a /test/codegen/bits.go | |
| parent | af8f94e3c5885647d6f85d2d5227b5fc6b637c52 (diff) | |
| download | go-5e4000ad7ff153d90e77c97d7f29d3a2fa6c7de0.tar.xz | |
cmd/compile: on PPC64, fix sign/zero extension when masking
(ANDCCconst [y] (MOV.*reg x)) should only be merged when zero
extending. Otherwise, sign bits are lost on negative values.
(ANDCCconst [0xFF] (MOVBreg x)) should be simplified to a zero
extension of x. Likewise for the MOVHreg variant.
Fixes #61297
Change-Id: I04e4fd7dc6a826e870681f37506620d48393698b
Reviewed-on: https://go-review.googlesource.com/c/go/+/508775
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Diffstat (limited to 'test/codegen/bits.go')
| -rw-r--r-- | test/codegen/bits.go | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/test/codegen/bits.go b/test/codegen/bits.go index 4f70627c25..018f5b909e 100644 --- a/test/codegen/bits.go +++ b/test/codegen/bits.go @@ -374,3 +374,23 @@ func foldConstOutOfRange(a uint64) uint64 { // arm64: "MOVD\t[$]19088744",-"ADD\t[$]19088744" return a + 0x1234568 } + +// Verify sign-extended values are not zero-extended under a bit mask (#61297) +func signextendAndMask8to64(a int8) (s, z uint64) { + // ppc64x: "MOVB", "ANDCC\t[$]1015," + s = uint64(a) & 0x3F7 + // ppc64x: -"MOVB", "ANDCC\t[$]247," + z = uint64(uint8(a)) & 0x3F7 + return + +} + +// Verify zero-extended values are not sign-extended under a bit mask (#61297) +func zeroextendAndMask8to64(a int8, b int16) (x, y uint64) { + // ppc64x: -"MOVB\t", -"ANDCC", "MOVBZ" + x = uint64(a) & 0xFF + // ppc64x: -"MOVH\t", -"ANDCC", "MOVHZ" + y = uint64(b) & 0xFFFF + return + +} |