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| author | Michael Munday <munday@ca.ibm.com> | 2016-04-10 20:01:49 -0400 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2016-04-11 18:53:36 +0000 |
| commit | cd6b2b7451c6feb277d38820f41f81ce4a036af2 (patch) | |
| tree | 4c27f58cd9e0c84b95e4dc4edb02d86f85cec3f9 /src/cmd/asm | |
| parent | cabb1402568ae7d05d9d5adf56953a4792085a81 (diff) | |
| download | go-cd6b2b7451c6feb277d38820f41f81ce4a036af2.tar.xz | |
cmd/internal/obj/s390x: add MULHD instruction
Emulate 64-bit signed high multiplication ((a*b)>>64). To do this
we use the 64-bit unsigned high multiplication method and then
fix the result as shown in Hacker's Delight 2nd ed., chapter 8-3.
Required to enable some division optimizations.
Change-Id: I9194f428e09d3d029cb1afb4715cd5424b5d922e
Reviewed-on: https://go-review.googlesource.com/21774
Reviewed-by: Bill O'Farrell <billotosyr@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/cmd/asm')
| -rw-r--r-- | src/cmd/asm/internal/asm/testdata/s390x.s | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/cmd/asm/internal/asm/testdata/s390x.s b/src/cmd/asm/internal/asm/testdata/s390x.s index 148cd2eaae..f1dc9aff2d 100644 --- a/src/cmd/asm/internal/asm/testdata/s390x.s +++ b/src/cmd/asm/internal/asm/testdata/s390x.s @@ -61,6 +61,10 @@ TEXT main·foo(SB),7,$16-0 // TEXT main.foo(SB), 7, $16-0 MULLW R6, R7, R8 // b9040087b91c0086 MULLW $8192, R6 // c26000002000 MULLW $8192, R6, R7 // b9040076c27000002000 + MULHD R9, R8 // b90400b8b98600a9ebb9003f000ab98000b8b90900abebb8003f000ab98000b9b9e9b08a + MULHD R7, R2, R1 // b90400b2b98600a7ebb7003f000ab98000b2b90900abebb2003f000ab98000b7b9e9b01a + MULHDU R3, R4 // b90400b4b98600a3b904004a + MULHDU R5, R6, R7 // b90400b6b98600a5b904007a DIVD R1, R2 // b90400b2b90d00a1b904002b DIVD R1, R2, R3 // b90400b2b90d00a1b904003b DIVW R4, R5 // b90400b5b91d00a4b904005b |