Hello! Attached patch corrects "C" constraint to accept only SSE constant zero operand and introduces new "BC" constraint to accept all SSE constant operands (all bits 0 and all bits 1).
As discussed in the PR, the compiler ICEs when "C" constraint is used non-zero vector operands, so it is still possible to change the constraint a bit. With fixed constraint, we get "impossible constraint" error instead of ICEing when following testcase: --cut here-- typedef int __v4si __attribute__ ((__vector_size__ (16))); void test (void) { asm volatile ("%0" : : "C" ( (__v4si) { -1, -1, -1, -1 } )); } --cut here-- is compiled with -O2 -msse2. 2016-01-28 Uros Bizjak <ubiz...@gmail.com> PR target/69459 * config/i386/constraints.md (C): Only accept constant zero operand. (BC): New constraint. * config/i386/sse.md (*mov<mode>_internal): Use BC constraint instead of C constraint. * doc/md.texi (Machine Constraints): Update description of C constraint. testsuite/ChangeLog: 2016-01-28 Uros Bizjak <ubiz...@gmail.com> PR target/69459 * gcc.target/i386/pr69459.c: New test. Patch was bootstrapped and regression tested on x86_64-linux-gnu {,-m32}. Patch was committed to mainline SVN and will be backported to release branches. Uros.
Index: config/i386/constraints.md =================================================================== --- config/i386/constraints.md (revision 232929) +++ config/i386/constraints.md (working copy) @@ -152,6 +152,7 @@ ;; s Sibcall memory operand, not valid for TARGET_X32 ;; w Call memory operand, not valid for TARGET_X32 ;; z Constant call address operand. +;; C SSE constant operand. (define_constraint "Bf" "@internal Flags register operand." @@ -183,6 +184,10 @@ "@internal Constant call address operand." (match_operand 0 "constant_call_address_operand")) +(define_constraint "BC" + "@internal SSE constant operand." + (match_test "standard_sse_constant_p (op)")) + ;; Integer constant constraints. (define_constraint "I" "Integer constant in the range 0 @dots{} 31, for 32-bit shifts." @@ -233,8 +238,8 @@ ;; This can theoretically be any mode's CONST0_RTX. (define_constraint "C" - "Standard SSE floating point constant." - (match_test "standard_sse_constant_p (op)")) + "SSE constant zero operand." + (match_test "standard_sse_constant_p (op) == 1")) ;; Constant-or-symbol-reference constraints. Index: config/i386/sse.md =================================================================== --- config/i386/sse.md (revision 232929) +++ config/i386/sse.md (working copy) @@ -833,7 +833,7 @@ (define_insn "*mov<mode>_internal" [(set (match_operand:VMOVE 0 "nonimmediate_operand" "=v,v ,m") - (match_operand:VMOVE 1 "nonimmediate_or_sse_const_operand" "C ,vm,v"))] + (match_operand:VMOVE 1 "nonimmediate_or_sse_const_operand" "BC,vm,v"))] "TARGET_SSE && (register_operand (operands[0], <MODE>mode) || register_operand (operands[1], <MODE>mode))" Index: doc/md.texi =================================================================== --- doc/md.texi (revision 232929) +++ doc/md.texi (working copy) @@ -4100,7 +4100,7 @@ Integer constant in the range 0 @dots{} 127, for 1 Standard 80387 floating point constant. @item C -Standard SSE floating point constant. +SSE constant zero operand. @item e 32-bit signed integer constant, or a symbolic reference known Index: testsuite/gcc.target/i386/pr69459.c =================================================================== --- testsuite/gcc.target/i386/pr69459.c (nonexistent) +++ testsuite/gcc.target/i386/pr69459.c (working copy) @@ -0,0 +1,42 @@ +/* PR target/69549 */ +/* { dg-do run { target sse2_runtime } } */ +/* { dg-options "-O2 -msse2" } */ + +typedef unsigned char u8; +typedef unsigned short u16; +typedef unsigned int u32; +typedef unsigned long long u64; +typedef unsigned char v16u8 __attribute__ ((vector_size (16))); +typedef unsigned short v16u16 __attribute__ ((vector_size (16))); +typedef unsigned int v16u32 __attribute__ ((vector_size (16))); +typedef unsigned long long v16u64 __attribute__ ((vector_size (16))); + +u64 __attribute__((noinline, noclone)) +foo (u8 u8_0, u16 u16_3, v16u8 v16u8_0, v16u16 v16u16_0, v16u32 v16u32_0, v16u64 v16u64_0, v16u8 v16u8_1, v16u16 v16u16_1, v16u32 v16u32_1, v16u64 v16u64_1, v16u8 v16u8_2, v16u16 v16u16_2, v16u32 v16u32_2, v16u64 v16u64_2, v16u8 v16u8_3, v16u16 v16u16_3, v16u32 v16u32_3, v16u64 v16u64_3) +{ + v16u64_0 /= (v16u64){u16_3, ((0))} | 1; + v16u64_1 += (v16u64)~v16u32_0; + v16u16_1 /= (v16u16){-v16u64_3[1]} | 1; + v16u64_3[1] -= 0x1fffffff; + v16u32_2 /= (v16u32)-v16u64_0 | 1; + v16u32_1 += ~v16u32_1; + v16u16_3 %= (v16u16){0xfff, v16u32_2[3], v16u8_0[14]} | 1; + v16u64_3 -= (v16u64)v16u32_2; + if (v16u64_1[1] >= 1) { + v16u64_0 %= (v16u64){v16u32_0[1]} | 1; + v16u32_1[1] %= 0x5fb856; + v16u64_1 |= -v16u64_0; + } + v16u8_0 *= (v16u8)v16u32_1; + return u8_0 + v16u8_0 [12] + v16u8_0 [13] + v16u8_0 [14] + v16u8_0 [15] + v16u16_0 [0] + v16u16_0 [1] + v16u32_0 [0] + v16u32_0 [1] + v16u32_0 [2] + v16u32_0 [3] + v16u64_0 [0] + v16u64_0 [1] + v16u8_1 [9] + v16u8_1 [10] + v16u8_1 [11] + v16u8_1 [15] + v16u16_1 [0] + v16u16_1 [1] + v16u16_1 [3] + v16u64_1 [0] + v16u64_1 [1] + v16u8_2 [3] + v16u8_2 [4] + v16u8_2 [5] + v16u8_2 [0] + v16u32_2 [1] + v16u32_2 [2] + v16u32_2 [3] + v16u64_2 [0] + v16u64_2 [1] + v16u8_3 [0] + v16u16_3 [6] + v16u16_3[7] + v16u32_3[1] + v16u32_3[2] + v16u64_3[0] + v16u64_3[1]; +} + +int +main () +{ + u64 x = foo(1, 1, (v16u8){1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, (v16u16){1, 1}, (v16u32){1}, (v16u64){1}, (v16u8){1}, (v16u16){1, 1}, (v16u32){1}, (v16u64){1}, (v16u8){1, 1, 1, 1, 1}, (v16u16){1}, (v16u32){1}, (v16u64){1}, (v16u8){1}, (v16u16){1}, (v16u32){1}, (v16u64){1}); + + if (x != 0xffffffffe0000209) + __builtin_abort(); + return 0; +}