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

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>

diff --git a/src/cmd/asm/internal/asm/testdata/ppc64.s b/src/cmd/asm/internal/asm/testdata/ppc64.s
index 5cff82ff36b333c1130e25ba5f9e6389509e73c0..367d7b77db0ba58d07af3fb1dd851dd1757ae8c8 100644 (file)
--- a/src/cmd/asm/internal/asm/testdata/ppc64.s
+++ b/src/cmd/asm/internal/asm/testdata/ppc64.s
@@ -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

diff --git a/src/cmd/internal/obj/ppc64/obj9.go b/src/cmd/internal/obj/ppc64/obj9.go
index 84ba28211d593b0cf914af07376afd890861f927..47ad85e79c66fc89859da761327df6076bb91591 100644 (file)
--- a/src/cmd/internal/obj/ppc64/obj9.go
+++ b/src/cmd/internal/obj/ppc64/obj9.go
@@ -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

diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index 817d13a9eca4d74d16537aa0de41c21c58d42822..d0427a4807f37f6dcda6fce3a925f1dc8fe6cb88 100644 (file)
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -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