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cmd/internal/obj/ppc64: generate big uint32 values in register

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When using "MOVD $const, Rx", any 32b constant can be generated in
register quickly. Avoid transforming big uint32 values into a load.

And, fix the instance in runtime.usleep where I discovered this.

Change-Id: I46e156d7edf200f85b5b61162f00223c0ad81fe2
Reviewed-on: https://go-review.googlesource.com/c/go/+/444815
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Paul Murphy <murp@ibm.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
This commit is contained in:
Paul E. Murphy 2022-10-21 09:19:47 -05:00 committed by Paul Murphy
parent f9ee56145b
commit 4e6f90fecd
3 changed files with 11 additions and 4 deletions
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5
src/cmd/asm/internal/asm/testdata/ppc64.s vendored
View File

@ -28,6 +28,11 @@ TEXT asmtest(SB),DUPOK|NOSPLIT,$0
MOVW $-32767, R5 // 38a08001
MOVW $-32768, R6 // 38c08000
MOVW $1234567, R5 // 6405001260a5d687
// Hex constant 0x80000001
MOVW $2147483649, R5 // 6405800060a50001
MOVD $2147483649, R5 // 6405800060a50001
// Hex constant 0xFFFFFFFF80000001
MOVD $-2147483647, R5 // 3ca0800060a50001
MOVD 8(R3), R4 // e8830008
MOVD (R3)(R4), R5 // 7ca4182a
MOVD (R3)(R0), R5 // 7ca0182a

7
src/cmd/internal/obj/ppc64/obj9.go
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@ -78,9 +78,12 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
}
}
// Put >32-bit constants in memory and load them
case AMOVD:
if p.From.Type == obj.TYPE_CONST && p.From.Name == obj.NAME_NONE && p.From.Reg == 0 && int64(int32(p.From.Offset)) != p.From.Offset {
// 32b constants (signed and unsigned) can be generated via 1 or 2 instructions.
// All others must be placed in memory and loaded.
isS32 := int64(int32(p.From.Offset)) == p.From.Offset
isU32 := uint64(uint32(p.From.Offset)) == uint64(p.From.Offset)
if p.From.Type == obj.TYPE_CONST && p.From.Name == obj.NAME_NONE && p.From.Reg == 0 && !isS32 && !isU32 {
p.From.Type = obj.TYPE_MEM
p.From.Sym = ctxt.Int64Sym(p.From.Offset)
p.From.Name = obj.NAME_EXTERN

3
src/runtime/sys_linux_ppc64x.s
View File

@ -112,8 +112,7 @@ TEXT runtime·usleep(SB),NOSPLIT,$16-4
// Use magic constant 0x8637bd06 and shift right 51
// to perform usec/1000000.
ORIS $0x8637, R0, R4 // Note, R0 always contains 0 here.
OR $0xbd06, R4, R4
MOVD $0x8637bd06, R4
MULLD R3, R4, R4 // Convert usec to S.
SRD $51, R4, R4
MOVD R4, 8(R1) // Store to tv_sec