cmd/compile: mark CMOVLEQF, CMOVWEQF as cloberring AX

Code generation for OpAMD64CMOV[WLQ]EQF uses AX as a scratch register,
but only CMOVQEQF, correctly lets compiler know. Mark other 2 as
clobbering AX.

Fixes #26097

Change-Id: I2a65bd67bf18a540898b4a0ae6c8766e0b767b19
Reviewed-on: https://go-review.googlesource.com/121336
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Giovanni Bajo <rasky@develer.com>

diff --git a/src/cmd/compile/internal/ssa/gen/AMD64Ops.go b/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
index 28694e435e58a41ad0a9f28a774def2feb2809f9..5a8634abd181fafc631aa71b0044e3a67e5e9ab3 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
@@ -397,11 +397,11 @@ func init() {
                {name: "CMOVQNEF", argLength: 3, reg: gp21, asm: "CMOVQNE", resultInArg0: true},
                {name: "CMOVQGTF", argLength: 3, reg: gp21, asm: "CMOVQHI", resultInArg0: true},
                {name: "CMOVQGEF", argLength: 3, reg: gp21, asm: "CMOVQCC", resultInArg0: true},
-               {name: "CMOVLEQF", argLength: 3, reg: gp21, asm: "CMOVLNE", resultInArg0: true},
+               {name: "CMOVLEQF", argLength: 3, reg: gp21pax, asm: "CMOVLNE", resultInArg0: true},
                {name: "CMOVLNEF", argLength: 3, reg: gp21, asm: "CMOVLNE", resultInArg0: true},
                {name: "CMOVLGTF", argLength: 3, reg: gp21, asm: "CMOVLHI", resultInArg0: true},
                {name: "CMOVLGEF", argLength: 3, reg: gp21, asm: "CMOVLCC", resultInArg0: true},
-               {name: "CMOVWEQF", argLength: 3, reg: gp21, asm: "CMOVWNE", resultInArg0: true},
+               {name: "CMOVWEQF", argLength: 3, reg: gp21pax, asm: "CMOVWNE", resultInArg0: true},
                {name: "CMOVWNEF", argLength: 3, reg: gp21, asm: "CMOVWNE", resultInArg0: true},
                {name: "CMOVWGTF", argLength: 3, reg: gp21, asm: "CMOVWHI", resultInArg0: true},
                {name: "CMOVWGEF", argLength: 3, reg: gp21, asm: "CMOVWCC", resultInArg0: true},

diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
index 01ce5e9e7d1c4b11bf69ba0ca766865a91c687b4..4924947d8b46c933a44a5e9c6d7fccc7de4da3e8 100644 (file)
--- a/src/cmd/compile/internal/ssa/opGen.go
+++ b/src/cmd/compile/internal/ssa/opGen.go
@@ -7956,11 +7956,12 @@ var opcodeTable = [...]opInfo{
                asm:          x86.ACMOVLNE,
                reg: regInfo{
                        inputs: []inputInfo{
-                               {0, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
+                               {0, 65518}, // CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                                {1, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                        },
+                       clobbers: 1, // AX
                        outputs: []outputInfo{
-                               {0, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
+                               {0, 65518}, // CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                        },
                },
        },
@@ -8016,11 +8017,12 @@ var opcodeTable = [...]opInfo{
                asm:          x86.ACMOVWNE,
                reg: regInfo{
                        inputs: []inputInfo{
-                               {0, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
+                               {0, 65518}, // CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                                {1, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                        },
+                       clobbers: 1, // AX
                        outputs: []outputInfo{
-                               {0, 65519}, // AX CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
+                               {0, 65518}, // CX DX BX BP SI DI R8 R9 R10 R11 R12 R13 R14 R15
                        },
                },
        },

diff --git a/test/fixedbugs/issue26097.go b/test/fixedbugs/issue26097.go
new file mode 100644 (file)
index 0000000..eedd6ba
--- /dev/null
+++ b/test/fixedbugs/issue26097.go
@@ -0,0 +1,47 @@
+// run
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+//go:noinline
+func cmovClobberAX64(v1, v2 int64, x1, x2 float64) int64 {
+       r := v1
+       if x1 == x2 {
+               r = v2
+       }
+       return r
+}
+
+//go:noinline
+func cmovClobberAX32(v1, v2 int32, x1, x2 float64) int32 {
+       r := v1
+       if x1 == x2 {
+               r = v2
+       }
+       return r
+}
+
+//go:noinline
+func cmovClobberAX16(v1, v2 int16, x1, x2 float64) int16 {
+       r := v1
+       if x1 == x2 {
+               r = v2
+       }
+       return r
+}
+
+func main() {
+       if cmovClobberAX16(1, 2, 4.0, 5.0) != 1 {
+               panic("CMOVQEQF causes incorrect code")
+       }
+       if cmovClobberAX32(1, 2, 4.0, 5.0) != 1 {
+               panic("CMOVQEQF causes incorrect code")
+       }
+       if cmovClobberAX64(1, 2, 4.0, 5.0) != 1 {
+               panic("CMOVQEQF causes incorrect code")
+       }
+
+}