On Wed, 2019-04-10 at 11:10 +0100, Richard Earnshaw (lists) wrote:
>
> OK with those changes.
>
> R.
I made the changes you suggested and checked in the patch. Just to be
complete, here is the final version of the patch that I checked in.
2018-04-10 Steve Ellcey <[email protected]>
PR rtl-optimization/87763
* config/aarch64/aarch64-protos.h (aarch64_masks_and_shift_for_bfi_p):
New prototype.
* config/aarch64/aarch64.c (aarch64_masks_and_shift_for_bfi_p):
New function.
* config/aarch64/aarch64.md (*aarch64_bfi<GPI:mode>5_shift):
New instruction.
(*aarch64_bfi<GPI:mode>5_shift_alt): Ditto.
(*aarch64_bfi<GPI:mode>4_noand): Ditto.
(*aarch64_bfi<GPI:mode>4_noand_alt): Ditto.
(*aarch64_bfi<GPI:mode>4_noshift): Ditto.
2018-04-10 Steve Ellcey <[email protected]>
PR rtl-optimization/87763
* gcc.target/aarch64/combine_bfxil.c: Change some bfxil checks
to bfi.
* gcc.target/aarch64/combine_bfi_2.c: New test.
diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index b035e35..b6c0d0a 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -429,6 +429,9 @@ bool aarch64_label_mentioned_p (rtx);
void aarch64_declare_function_name (FILE *, const char*, tree);
bool aarch64_legitimate_pic_operand_p (rtx);
bool aarch64_mask_and_shift_for_ubfiz_p (scalar_int_mode, rtx, rtx);
+bool aarch64_masks_and_shift_for_bfi_p (scalar_int_mode, unsigned HOST_WIDE_INT,
+ unsigned HOST_WIDE_INT,
+ unsigned HOST_WIDE_INT);
bool aarch64_zero_extend_const_eq (machine_mode, rtx, machine_mode, rtx);
bool aarch64_move_imm (HOST_WIDE_INT, machine_mode);
opt_machine_mode aarch64_sve_pred_mode (unsigned int);
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 95e5b03..9be7548 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -9336,6 +9336,35 @@ aarch64_mask_and_shift_for_ubfiz_p (scalar_int_mode mode, rtx mask,
& ((HOST_WIDE_INT_1U << INTVAL (shft_amnt)) - 1)) == 0;
}
+/* Return true if the masks and a shift amount from an RTX of the form
+ ((x & MASK1) | ((y << SHIFT_AMNT) & MASK2)) are valid to combine into
+ a BFI instruction of mode MODE. See *arch64_bfi patterns. */
+
+bool
+aarch64_masks_and_shift_for_bfi_p (scalar_int_mode mode,
+ unsigned HOST_WIDE_INT mask1,
+ unsigned HOST_WIDE_INT shft_amnt,
+ unsigned HOST_WIDE_INT mask2)
+{
+ unsigned HOST_WIDE_INT t;
+
+ /* Verify that there is no overlap in what bits are set in the two masks. */
+ if (mask1 != ~mask2)
+ return false;
+
+ /* Verify that mask2 is not all zeros or ones. */
+ if (mask2 == 0 || mask2 == HOST_WIDE_INT_M1U)
+ return false;
+
+ /* The shift amount should always be less than the mode size. */
+ gcc_assert (shft_amnt < GET_MODE_BITSIZE (mode));
+
+ /* Verify that the mask being shifted is contiguous and would be in the
+ least significant bits after shifting by shft_amnt. */
+ t = mask2 + (HOST_WIDE_INT_1U << shft_amnt);
+ return (t == (t & -t));
+}
+
/* Calculate the cost of calculating X, storing it in *COST. Result
is true if the total cost of the operation has now been calculated. */
static bool
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index ab8786a..e0df975 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -5491,6 +5491,94 @@
[(set_attr "type" "bfm")]
)
+;; Match a bfi instruction where the shift of OP3 means that we are
+;; actually copying the least significant bits of OP3 into OP0 by way
+;; of the AND masks and the IOR instruction. A similar instruction
+;; with the two parts of the IOR swapped around was never triggered
+;; in a bootstrap build and test of GCC so it was not included.
+
+(define_insn "*aarch64_bfi<GPI:mode>5_shift"
+ [(set (match_operand:GPI 0 "register_operand" "=r")
+ (ior:GPI (and:GPI (match_operand:GPI 1 "register_operand" "0")
+ (match_operand:GPI 2 "const_int_operand" "n"))
+ (and:GPI (ashift:GPI
+ (match_operand:GPI 3 "register_operand" "r")
+ (match_operand:GPI 4 "aarch64_simd_shift_imm_<mode>" "n"))
+ (match_operand:GPI 5 "const_int_operand" "n"))))]
+ "aarch64_masks_and_shift_for_bfi_p (<MODE>mode, UINTVAL (operands[2]),
+ UINTVAL (operands[4]),
+ UINTVAL(operands[5]))"
+ "bfi\t%<GPI:w>0, %<GPI:w>3, %4, %P5"
+ [(set_attr "type" "bfm")]
+)
+
+(define_insn "*aarch64_bfi<GPI:mode>5_shift_alt"
+ [(set (match_operand:GPI 0 "register_operand" "=r")
+ (ior:GPI (and:GPI (ashift:GPI
+ (match_operand:GPI 1 "register_operand" "r")
+ (match_operand:GPI 2 "aarch64_simd_shift_imm_<mode>" "n"))
+ (match_operand:GPI 3 "const_int_operand" "n"))
+ (and:GPI (match_operand:GPI 4 "register_operand" "0")
+ (match_operand:GPI 5 "const_int_operand" "n"))))]
+ "aarch64_masks_and_shift_for_bfi_p (<MODE>mode, UINTVAL (operands[5]),
+ UINTVAL (operands[2]),
+ UINTVAL(operands[3]))"
+ "bfi\t%<GPI:w>0, %<GPI:w>1, %2, %P3"
+ [(set_attr "type" "bfm")]
+)
+
+;; Like *aarch64_bfi<GPI:mode>5_shift but with no and of the ashift because
+;; the shift is large enough to remove the need for an AND instruction.
+
+(define_insn "*aarch64_bfi<GPI:mode>4_noand"
+ [(set (match_operand:GPI 0 "register_operand" "=r")
+ (ior:GPI (and:GPI (match_operand:GPI 1 "register_operand" "0")
+ (match_operand:GPI 2 "const_int_operand" "n"))
+ (ashift:GPI
+ (match_operand:GPI 3 "register_operand" "r")
+ (match_operand:GPI 4 "aarch64_simd_shift_imm_<mode>" "n"))))]
+ "aarch64_masks_and_shift_for_bfi_p (<MODE>mode, UINTVAL (operands[2]),
+ UINTVAL (operands[4]),
+ HOST_WIDE_INT_M1U << UINTVAL (operands[4]) )"
+{
+ operands[5] = GEN_INT (GET_MODE_BITSIZE (<MODE>mode) - UINTVAL (operands[4]));
+ return "bfi\t%<GPI:w>0, %<GPI:w>3, %4, %5";
+}
+ [(set_attr "type" "bfm")]
+)
+
+(define_insn "*aarch64_bfi<GPI:mode>4_noand_alt"
+ [(set (match_operand:GPI 0 "register_operand" "=r")
+ (ior:GPI (ashift:GPI
+ (match_operand:GPI 1 "register_operand" "r")
+ (match_operand:GPI 2 "aarch64_simd_shift_imm_<mode>" "n"))
+ (and:GPI (match_operand:GPI 3 "register_operand" "0")
+ (match_operand:GPI 4 "const_int_operand" "n"))))]
+ "aarch64_masks_and_shift_for_bfi_p (<MODE>mode, UINTVAL (operands[4]),
+ UINTVAL (operands[2]),
+ HOST_WIDE_INT_M1U << UINTVAL (operands[2]) )"
+{
+ operands[5] = GEN_INT (GET_MODE_BITSIZE (<MODE>mode) - UINTVAL (operands[2]));
+ return "bfi\t%<GPI:w>0, %<GPI:w>1, %2, %5";
+}
+ [(set_attr "type" "bfm")]
+)
+
+;; Like *aarch64_bfi<GPI:mode>5_shift but with no shifting, we are just
+;; copying the least significant bits of OP3 to OP0.
+
+(define_insn "*aarch64_bfi<GPI:mode>4_noshift"
+ [(set (match_operand:GPI 0 "register_operand" "=r")
+ (ior:GPI (and:GPI (match_operand:GPI 1 "register_operand" "0")
+ (match_operand:GPI 2 "const_int_operand" "n"))
+ (and:GPI (match_operand:GPI 3 "register_operand" "r")
+ (match_operand:GPI 4 "const_int_operand" "n"))))]
+ "aarch64_masks_and_shift_for_bfi_p (<MODE>mode, UINTVAL (operands[2]), 0,
+ UINTVAL (operands[4]))"
+ "bfi\t%<GPI:w>0, %<GPI:w>3, 0, %P4"
+ [(set_attr "type" "bfm")]
+)
+
(define_insn "*extr_insv_lower_reg<mode>"
[(set (zero_extract:GPI (match_operand:GPI 0 "register_operand" "+r")
(match_operand 1 "const_int_operand" "n")
diff --git a/gcc/testsuite/gcc.target/aarch64/combine_bfi_2.c b/gcc/testsuite/gcc.target/aarch64/combine_bfi_2.c
index e69de29..145282d 100644
--- a/gcc/testsuite/gcc.target/aarch64/combine_bfi_2.c
+++ b/gcc/testsuite/gcc.target/aarch64/combine_bfi_2.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int f1(int x, int y)
+{
+ return (y & 0xfffffff) | (((x <<28) & 0xf0000000));
+}
+
+
+int f2(int x, int y)
+{
+ return (((x <<28) & 0xf0000000)) | (y & 0xfffffff);
+}
+
+/* { dg-final { scan-assembler-times {\tbfi\t} 2 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/combine_bfxil.c b/gcc/testsuite/gcc.target/aarch64/combine_bfxil.c
index 109f989..a2fb31c 100644
--- a/gcc/testsuite/gcc.target/aarch64/combine_bfxil.c
+++ b/gcc/testsuite/gcc.target/aarch64/combine_bfxil.c
@@ -114,4 +114,5 @@ main (void)
return 0;
}
-/* { dg-final { scan-assembler-times "bfxil\\t" 18 } } */
+/* { dg-final { scan-assembler-times "bfxil\\t" 7 } } */
+/* { dg-final { scan-assembler-times "bfi\\t" 11 } } */
