On Tue, 2024-11-26 at 18:37 +0800, Jinyang He wrote:
> For {xv,v}{srl,sll,sra}, the constraint `vector_same_uimm6` cause overflow
> in when emit {w,h,b}. Since the number of bits shifted is the remainder of
> the register value, it is actually unnecessary to constrain the range.
> Simply mask the shift number with the unit-bit-width, without any
> constraint on the shift range.
Some comments below.
/* snip */
> diff --git a/gcc/config/loongarch/lasx.md b/gcc/config/loongarch/lasx.md
> index 457ed163f31..da3bc758a29 100644
> --- a/gcc/config/loongarch/lasx.md
> +++ b/gcc/config/loongarch/lasx.md
> @@ -1013,11 +1013,23 @@
> [(set (match_operand:ILASX 0 "register_operand" "=f,f")
> (lshiftrt:ILASX
> (match_operand:ILASX 1 "register_operand" "f,f")
> - (match_operand:ILASX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILASX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LASX"
> - "@
> - xvsrl.<lasxfmt>\t%u0,%u1,%u2
> - xvsrli.<lasxfmt>\t%u0,%u1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "xvsrl.<lasxfmt>\t%u0,%u1,%u2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "xvsrli.<lasxfmt>\t%u0,%u1,%d2";
Incorrect indent. Check editor and mail client setting?
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> @@ -1026,11 +1038,23 @@
> [(set (match_operand:ILASX 0 "register_operand" "=f,f")
> (ashiftrt:ILASX
> (match_operand:ILASX 1 "register_operand" "f,f")
> - (match_operand:ILASX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILASX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LASX"
> - "@
> - xvsra.<lasxfmt>\t%u0,%u1,%u2
> - xvsrai.<lasxfmt>\t%u0,%u1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "xvsra.<lasxfmt>\t%u0,%u1,%u2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "xvsrai.<lasxfmt>\t%u0,%u1,%d2";
Likewise.
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> @@ -1039,11 +1063,23 @@
> [(set (match_operand:ILASX 0 "register_operand" "=f,f")
> (ashift:ILASX
> (match_operand:ILASX 1 "register_operand" "f,f")
> - (match_operand:ILASX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILASX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LASX"
> - "@
> - xvsll.<lasxfmt>\t%u0,%u1,%u2
> - xvslli.<lasxfmt>\t%u0,%u1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "xvsll.<lasxfmt>\t%u0,%u1,%u2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "xvslli.<lasxfmt>\t%u0,%u1,%d2";
Likewise.
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> diff --git a/gcc/config/loongarch/loongarch-protos.h
> b/gcc/config/loongarch/loongarch-protos.h
> index bc1b94b41d3..be37f284f39 100644
> --- a/gcc/config/loongarch/loongarch-protos.h
> +++ b/gcc/config/loongarch/loongarch-protos.h
> @@ -113,8 +113,9 @@ extern rtx loongarch_return_addr (int, rtx);
>
> extern bool loongarch_const_vector_same_val_p (rtx, machine_mode);
> extern bool loongarch_const_vector_same_bytes_p (rtx, machine_mode);
> -extern bool loongarch_const_vector_same_int_p (rtx, machine_mode,
> HOST_WIDE_INT,
> - HOST_WIDE_INT);
> +extern bool loongarch_const_vector_same_int_p (rtx, machine_mode,
> + HOST_WIDE_INT low = HOST_WIDE_INT_MIN,
> + HOST_WIDE_INT high = HOST_WIDE_INT_MAX);
> extern bool loongarch_const_vector_shuffle_set_p (rtx, machine_mode);
> extern bool loongarch_const_vector_bitimm_set_p (rtx, machine_mode);
> extern bool loongarch_const_vector_bitimm_clr_p (rtx, machine_mode);
> diff --git a/gcc/config/loongarch/lsx.md b/gcc/config/loongarch/lsx.md
> index a9004290371..314544e012d 100644
> --- a/gcc/config/loongarch/lsx.md
> +++ b/gcc/config/loongarch/lsx.md
> @@ -879,11 +879,23 @@
> [(set (match_operand:ILSX 0 "register_operand" "=f,f")
> (lshiftrt:ILSX
> (match_operand:ILSX 1 "register_operand" "f,f")
> - (match_operand:ILSX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILSX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LSX"
> - "@
> - vsrl.<lsxfmt>\t%w0,%w1,%w2
> - vsrli.<lsxfmt>\t%w0,%w1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "vsrl.<lsxfmt>\t%w0,%w1,%w2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "vsrli.<lsxfmt>\t%w0,%w1,%d2";
Likewise.
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> @@ -891,11 +903,23 @@
> [(set (match_operand:ILSX 0 "register_operand" "=f,f")
> (ashiftrt:ILSX
> (match_operand:ILSX 1 "register_operand" "f,f")
> - (match_operand:ILSX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILSX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LSX"
> - "@
> - vsra.<lsxfmt>\t%w0,%w1,%w2
> - vsrai.<lsxfmt>\t%w0,%w1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "vsra.<lsxfmt>\t%w0,%w1,%w2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "vsrai.<lsxfmt>\t%w0,%w1,%d2";
Likewise.
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> @@ -903,11 +927,23 @@
> [(set (match_operand:ILSX 0 "register_operand" "=f,f")
> (ashift:ILSX
> (match_operand:ILSX 1 "register_operand" "f,f")
> - (match_operand:ILSX 2 "reg_or_vector_same_uimm6_operand" "f,Uuv6")))]
> + (match_operand:ILSX 2 "reg_or_vector_same_uimm_operand" "f,Uuvx")))]
> "ISA_HAS_LSX"
> - "@
> - vsll.<lsxfmt>\t%w0,%w1,%w2
> - vslli.<lsxfmt>\t%w0,%w1,%E2"
> +{
> + switch (which_alternative)
> + {
> + case 0:
> + return "vsll.<lsxfmt>\t%w0,%w1,%w2";
> + case 1:
> + {
> + unsigned HOST_WIDE_INT val = UINTVAL (CONST_VECTOR_ELT (operands[2], 0));
> + operands[2] = GEN_INT (val & (GET_MODE_UNIT_BITSIZE (<MODE>mode) - 1));
> + return "vslli.<lsxfmt>\t%w0,%w1,%d2";
Likewise.
> + }
> + default:
> + gcc_unreachable ();
> + }
> +}
> [(set_attr "type" "simd_shift")
> (set_attr "mode" "<MODE>")])
>
> diff --git a/gcc/config/loongarch/predicates.md
> b/gcc/config/loongarch/predicates.md
> index 95c2544cc2f..e744e4e61ea 100644
> --- a/gcc/config/loongarch/predicates.md
> +++ b/gcc/config/loongarch/predicates.md
> @@ -635,10 +635,10 @@
> return loongarch_const_vector_same_int_p (op, mode, -31, 31);
> })
>
> -(define_predicate "const_vector_same_uimm6_operand"
> +(define_predicate "const_vector_same_uimm_operand"
> (match_code "const_vector")
> {
> - return loongarch_const_vector_same_int_p (op, mode, 0, 63);
> + return loongarch_const_vector_same_int_p (op, mode);
> })
>
> (define_predicate "par_const_vector_shf_set_operand"
> @@ -663,6 +663,6 @@
> (ior (match_operand 0 "register_operand")
> (match_operand 0 "const_vector_same_ximm5_operand")))
>
> -(define_predicate "reg_or_vector_same_uimm6_operand"
> +(define_predicate "reg_or_vector_same_uimm_operand"
> (ior (match_operand 0 "register_operand")
> - (match_operand 0 "const_vector_same_uimm6_operand")))
> + (match_operand 0 "const_vector_same_uimm_operand")))
> diff --git
> a/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-shift-sameimm-vec.c
> b/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-shift-sameimm-vec.c
> new file mode 100644
> index 00000000000..73df6217c63
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-shift-sameimm-vec.c
> @@ -0,0 +1,72 @@
> +/* Test shift bits overflow in vector */
> +/* { dg-do compile } */
> +/* { dg-options "-mlasx -O2" } */
> +/* { dg-final { scan-assembler "xvslli.b.*,1" } } */
Am I correct that the issue has triggered an assembler error? IIUC we
can change it to "dg-do assemble" and then we don't need to have all
those scan-assembler.
/* snip */
> diff --git
> a/gcc/testsuite/gcc.target/loongarch/vector/lsx/lsx-shift-sameimm-vec.c
> b/gcc/testsuite/gcc.target/loongarch/vector/lsx/lsx-shift-sameimm-vec.c
> new file mode 100644
> index 00000000000..68e89e941e4
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/vector/lsx/lsx-shift-sameimm-vec.c
> @@ -0,0 +1,72 @@
> +/* Test shift bits overflow in vector */
> +/* { dg-do compile } */
> +/* { dg-options "-mlsx -O2" } */
> +/* { dg-final { scan-assembler "vslli.b.*,1" } } */
Likewise.
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
