1; RUN: llc < %s 2 3%Domain = type { ptr, i32, ptr, i32, i32, ptr, ptr } 4@AConst = constant i32 123 ; <ptr> [#uses=1] 5 6; Test setting values of different constants in registers. 7; 8define void @testConsts(i32 %N, float %X) { 9 %a = add i32 %N, 1 ; <i32> [#uses=0] 10 %i = add i32 %N, 12345678 ; <i32> [#uses=0] 11 %b = add i16 4, 3 ; <i16> [#uses=0] 12 %c = fadd float %X, 0.000000e+00 ; <float> [#uses=0] 13 %d = fadd float %X, 0x400921CAC0000000 ; <float> [#uses=0] 14 %f = add i32 -1, 10 ; <i32> [#uses=0] 15 %g = add i16 20, -1 ; <i16> [#uses=0] 16 %j = add i16 -1, 30 ; <i16> [#uses=0] 17 %h = add i8 40, -1 ; <i8> [#uses=0] 18 %k = add i8 -1, 50 ; <i8> [#uses=0] 19 ret void 20} 21 22; A SetCC whose result is used should produce instructions to 23; compute the boolean value in a register. One whose result 24; is unused will only generate the condition code but not 25; the boolean result. 26; 27define void @unusedBool(ptr %x, ptr %y) { 28 icmp eq ptr %x, %y ; <i1>:1 [#uses=1] 29 xor i1 %1, true ; <i1>:2 [#uses=0] 30 icmp ne ptr %x, %y ; <i1>:3 [#uses=0] 31 ret void 32} 33 34; A constant argument to a Phi produces a Cast instruction in the 35; corresponding predecessor basic block. This checks a few things: 36; -- phi arguments coming from the bottom of the same basic block 37; (they should not be forward substituted in the machine code!) 38; -- code generation for casts of various types 39; -- use of immediate fields for integral constants of different sizes 40; -- branch on a constant condition 41; 42define void @mergeConstants(ptr %x, ptr %y) { 43; <label>:0 44 br label %Top 45 46Top: ; preds = %Next, %Top, %0 47 phi i32 [ 0, %0 ], [ 1, %Top ], [ 524288, %Next ] ; <i32>:1 [#uses=0] 48 phi float [ 0.000000e+00, %0 ], [ 1.000000e+00, %Top ], [ 2.000000e+00, %Next ] ; <float>:2 [#uses=0] 49 phi double [ 5.000000e-01, %0 ], [ 1.500000e+00, %Top ], [ 2.500000e+00, %Next ] 50 phi i1 [ true, %0 ], [ false, %Top ], [ true, %Next ] ; <i1>:4 [#uses=0] 51 br i1 true, label %Top, label %Next 52 53Next: ; preds = %Top 54 br label %Top 55} 56 57 58 59; A constant argument to a cast used only once should be forward substituted 60; and loaded where needed, which happens is: 61; -- User of cast has no immediate field 62; -- User of cast has immediate field but constant is too large to fit 63; or constant is not resolved until later (e.g., global address) 64; -- User of cast uses it as a call arg. or return value so it is an implicit 65; use but has to be loaded into a virtual register so that the reg. 66; allocator can allocate the appropriate phys. reg. for it 67; 68define ptr @castconst(float) { 69 %castbig = trunc i64 99999999 to i32 ; <i32> [#uses=1] 70 %castsmall = trunc i64 1 to i32 ; <i32> [#uses=1] 71 %usebig = add i32 %castbig, %castsmall ; <i32> [#uses=0] 72 %dummyl = load i64, ptr @AConst ; <i64> [#uses=0] 73 %castnull = inttoptr i64 0 to ptr ; <ptr> [#uses=1] 74 ret ptr %castnull 75} 76 77; Test branch-on-comparison-with-zero, in two ways: 78; 1. can be folded 79; 2. cannot be folded because result of comparison is used twice 80; 81define void @testbool(i32 %A, i32 %B) { 82 br label %Top 83 84Top: ; preds = %loop, %0 85 %D = add i32 %A, %B ; <i32> [#uses=2] 86 %E = sub i32 %D, -4 ; <i32> [#uses=1] 87 %C = icmp sle i32 %E, 0 ; <i1> [#uses=1] 88 br i1 %C, label %retlbl, label %loop 89 90loop: ; preds = %loop, %Top 91 %F = add i32 %A, %B ; <i32> [#uses=0] 92 %G = sub i32 %D, -4 ; <i32> [#uses=1] 93 %D.upgrd.1 = icmp sle i32 %G, 0 ; <i1> [#uses=1] 94 %E.upgrd.2 = xor i1 %D.upgrd.1, true ; <i1> [#uses=1] 95 br i1 %E.upgrd.2, label %loop, label %Top 96 97retlbl: ; preds = %Top 98 ret void 99} 100 101 102;; Test use of a boolean result in cast operations. 103;; Requires converting a condition code result into a 0/1 value in a reg. 104;; 105define i32 @castbool(i32 %A, i32 %B) { 106bb0: 107 %cond213 = icmp slt i32 %A, %B ; <i1> [#uses=1] 108 %cast110 = zext i1 %cond213 to i8 ; <i8> [#uses=1] 109 %cast109 = zext i8 %cast110 to i32 ; <i32> [#uses=1] 110 ret i32 %cast109 111} 112 113;; Test use of a boolean result in arithmetic and logical operations. 114;; Requires converting a condition code result into a 0/1 value in a reg. 115;; 116define i1 @boolexpr(i1 %b, i32 %N) { 117 %b2 = icmp sge i32 %N, 0 ; <i1> [#uses=1] 118 %b3 = and i1 %b, %b2 ; <i1> [#uses=1] 119 ret i1 %b3 120} 121 122; Test branch on floating point comparison 123; 124define void @testfloatbool(float %x, float %y) { 125 br label %Top 126 127Top: ; preds = %Top, %0 128 %p = fadd float %x, %y ; <float> [#uses=1] 129 %z = fsub float %x, %y ; <float> [#uses=1] 130 %b = fcmp ole float %p, %z ; <i1> [#uses=2] 131 %c = xor i1 %b, true ; <i1> [#uses=0] 132 br i1 %b, label %Top, label %goon 133 134goon: ; preds = %Top 135 ret void 136} 137 138 139; Test cases where an LLVM instruction requires no machine 140; instructions (e.g., cast int* to long). But there are 2 cases: 141; 1. If the result register has only a single use and the use is in the 142; same basic block, the operand will be copy-propagated during 143; instruction selection. 144; 2. If the result register has multiple uses or is in a different 145; basic block, it cannot (or will not) be copy propagated during 146; instruction selection. It will generate a 147; copy instruction (add-with-0), but this copy should get coalesced 148; away by the register allocator. 149; 150define i32 @checkForward(i32 %N, ptr %A) { 151bb2: 152 %reg114 = shl i32 %N, 2 ; <i32> [#uses=1] 153 %cast115 = sext i32 %reg114 to i64 ; <i64> [#uses=1] 154 %cast116 = ptrtoint ptr %A to i64 ; <i64> [#uses=1] 155 %reg116 = add i64 %cast116, %cast115 ; <i64> [#uses=1] 156 %castPtr = inttoptr i64 %reg116 to ptr ; <ptr> [#uses=1] 157 %reg118 = load i32, ptr %castPtr ; <i32> [#uses=1] 158 %cast117 = sext i32 %reg118 to i64 ; <i64> [#uses=2] 159 %reg159 = add i64 1234567, %cast117 ; <i64> [#uses=0] 160 %reg160 = add i64 7654321, %cast117 ; <i64> [#uses=0] 161 ret i32 0 162} 163 164 165; Test case for unary NOT operation constructed from XOR. 166; 167define void @checkNot(i1 %b, i32 %i) { 168 %notB = xor i1 %b, true ; <i1> [#uses=1] 169 %notI = xor i32 %i, -1 ; <i32> [#uses=2] 170 %F = icmp sge i32 %notI, 100 ; <i1> [#uses=1] 171 %J = add i32 %i, %i ; <i32> [#uses=1] 172 %andNotB = and i1 %F, %notB ; <i1> [#uses=0] 173 %andNotI = and i32 %J, %notI ; <i32> [#uses=0] 174 %notB2 = xor i1 true, %b ; <i1> [#uses=0] 175 %notI2 = xor i32 -1, %i ; <i32> [#uses=0] 176 ret void 177} 178 179; Test case for folding getelementptr into a load/store 180; 181define i32 @checkFoldGEP(ptr %D, i64 %idx) { 182 %reg841 = getelementptr %Domain, ptr %D, i64 0, i32 1 ; <ptr> [#uses=1] 183 %reg820 = load i32, ptr %reg841 ; <i32> [#uses=1] 184 ret i32 %reg820 185} 186 187; Test case for scalarising a 1 element vselect 188; 189define <1 x i32> @checkScalariseVSELECT(<1 x i32> %a, <1 x i32> %b) { 190 %cond = icmp uge <1 x i32> %a, %b 191 %s = select <1 x i1> %cond, <1 x i32> %a, <1 x i32> %b 192 ret <1 x i32> %s 193} 194