; RUN: llc < %s %Domain = type { i8*, i32, i32*, i32, i32, i32*, %Domain* } @AConst = constant i32 123 ; <i32*> [#uses=1] ; Test setting values of different constants in registers. ; define void @testConsts(i32 %N, float %X) { %a = add i32 %N, 1 ; <i32> [#uses=0] %i = add i32 %N, 12345678 ; <i32> [#uses=0] %b = add i16 4, 3 ; <i16> [#uses=0] %c = fadd float %X, 0.000000e+00 ; <float> [#uses=0] %d = fadd float %X, 0x400921CAC0000000 ; <float> [#uses=0] %f = add i32 -1, 10 ; <i32> [#uses=0] %g = add i16 20, -1 ; <i16> [#uses=0] %j = add i16 -1, 30 ; <i16> [#uses=0] %h = add i8 40, -1 ; <i8> [#uses=0] %k = add i8 -1, 50 ; <i8> [#uses=0] ret void } ; A SetCC whose result is used should produce instructions to ; compute the boolean value in a register. One whose result ; is unused will only generate the condition code but not ; the boolean result. ; define void @unusedBool(i32* %x, i32* %y) { icmp eq i32* %x, %y ; <i1>:1 [#uses=1] xor i1 %1, true ; <i1>:2 [#uses=0] icmp ne i32* %x, %y ; <i1>:3 [#uses=0] ret void } ; A constant argument to a Phi produces a Cast instruction in the ; corresponding predecessor basic block. This checks a few things: ; -- phi arguments coming from the bottom of the same basic block ; (they should not be forward substituted in the machine code!) ; -- code generation for casts of various types ; -- use of immediate fields for integral constants of different sizes ; -- branch on a constant condition ; define void @mergeConstants(i32* %x, i32* %y) { ; <label>:0 br label %Top Top: ; preds = %Next, %Top, %0 phi i32 [ 0, %0 ], [ 1, %Top ], [ 524288, %Next ] ; <i32>:1 [#uses=0] phi float [ 0.000000e+00, %0 ], [ 1.000000e+00, %Top ], [ 2.000000e+00, %Next ] ; <float>:2 [#uses=0] phi double [ 5.000000e-01, %0 ], [ 1.500000e+00, %Top ], [ 2.500000e+00, %Next ] phi i1 [ true, %0 ], [ false, %Top ], [ true, %Next ] ; <i1>:4 [#uses=0] br i1 true, label %Top, label %Next Next: ; preds = %Top br label %Top } ; A constant argument to a cast used only once should be forward substituted ; and loaded where needed, which happens is: ; -- User of cast has no immediate field ; -- User of cast has immediate field but constant is too large to fit ; or constant is not resolved until later (e.g., global address) ; -- User of cast uses it as a call arg. or return value so it is an implicit ; use but has to be loaded into a virtual register so that the reg. ; allocator can allocate the appropriate phys. reg. for it ; define i32* @castconst(float) { %castbig = trunc i64 99999999 to i32 ; <i32> [#uses=1] %castsmall = trunc i64 1 to i32 ; <i32> [#uses=1] %usebig = add i32 %castbig, %castsmall ; <i32> [#uses=0] %castglob = bitcast i32* @AConst to i64* ; <i64*> [#uses=1] %dummyl = load i64* %castglob ; <i64> [#uses=0] %castnull = inttoptr i64 0 to i32* ; <i32*> [#uses=1] ret i32* %castnull } ; Test branch-on-comparison-with-zero, in two ways: ; 1. can be folded ; 2. cannot be folded because result of comparison is used twice ; define void @testbool(i32 %A, i32 %B) { br label %Top Top: ; preds = %loop, %0 %D = add i32 %A, %B ; <i32> [#uses=2] %E = sub i32 %D, -4 ; <i32> [#uses=1] %C = icmp sle i32 %E, 0 ; <i1> [#uses=1] br i1 %C, label %retlbl, label %loop loop: ; preds = %loop, %Top %F = add i32 %A, %B ; <i32> [#uses=0] %G = sub i32 %D, -4 ; <i32> [#uses=1] %D.upgrd.1 = icmp sle i32 %G, 0 ; <i1> [#uses=1] %E.upgrd.2 = xor i1 %D.upgrd.1, true ; <i1> [#uses=1] br i1 %E.upgrd.2, label %loop, label %Top retlbl: ; preds = %Top ret void } ;; Test use of a boolean result in cast operations. ;; Requires converting a condition code result into a 0/1 value in a reg. ;; define i32 @castbool(i32 %A, i32 %B) { bb0: %cond213 = icmp slt i32 %A, %B ; <i1> [#uses=1] %cast110 = zext i1 %cond213 to i8 ; <i8> [#uses=1] %cast109 = zext i8 %cast110 to i32 ; <i32> [#uses=1] ret i32 %cast109 } ;; Test use of a boolean result in arithmetic and logical operations. ;; Requires converting a condition code result into a 0/1 value in a reg. ;; define i1 @boolexpr(i1 %b, i32 %N) { %b2 = icmp sge i32 %N, 0 ; <i1> [#uses=1] %b3 = and i1 %b, %b2 ; <i1> [#uses=1] ret i1 %b3 } ; Test branch on floating point comparison ; define void @testfloatbool(float %x, float %y) { br label %Top Top: ; preds = %Top, %0 %p = fadd float %x, %y ; <float> [#uses=1] %z = fsub float %x, %y ; <float> [#uses=1] %b = fcmp ole float %p, %z ; <i1> [#uses=2] %c = xor i1 %b, true ; <i1> [#uses=0] br i1 %b, label %Top, label %goon goon: ; preds = %Top ret void } ; Test cases where an LLVM instruction requires no machine ; instructions (e.g., cast int* to long). But there are 2 cases: ; 1. If the result register has only a single use and the use is in the ; same basic block, the operand will be copy-propagated during ; instruction selection. ; 2. If the result register has multiple uses or is in a different ; basic block, it cannot (or will not) be copy propagated during ; instruction selection. It will generate a ; copy instruction (add-with-0), but this copy should get coalesced ; away by the register allocator. ; define i32 @checkForward(i32 %N, i32* %A) { bb2: %reg114 = shl i32 %N, 2 ; <i32> [#uses=1] %cast115 = sext i32 %reg114 to i64 ; <i64> [#uses=1] %cast116 = ptrtoint i32* %A to i64 ; <i64> [#uses=1] %reg116 = add i64 %cast116, %cast115 ; <i64> [#uses=1] %castPtr = inttoptr i64 %reg116 to i32* ; <i32*> [#uses=1] %reg118 = load i32* %castPtr ; <i32> [#uses=1] %cast117 = sext i32 %reg118 to i64 ; <i64> [#uses=2] %reg159 = add i64 1234567, %cast117 ; <i64> [#uses=0] %reg160 = add i64 7654321, %cast117 ; <i64> [#uses=0] ret i32 0 } ; Test case for unary NOT operation constructed from XOR. ; define void @checkNot(i1 %b, i32 %i) { %notB = xor i1 %b, true ; <i1> [#uses=1] %notI = xor i32 %i, -1 ; <i32> [#uses=2] %F = icmp sge i32 %notI, 100 ; <i1> [#uses=1] %J = add i32 %i, %i ; <i32> [#uses=1] %andNotB = and i1 %F, %notB ; <i1> [#uses=0] %andNotI = and i32 %J, %notI ; <i32> [#uses=0] %notB2 = xor i1 true, %b ; <i1> [#uses=0] %notI2 = xor i32 -1, %i ; <i32> [#uses=0] ret void } ; Test case for folding getelementptr into a load/store ; define i32 @checkFoldGEP(%Domain* %D, i64 %idx) { %reg841 = getelementptr %Domain* %D, i64 0, i32 1 ; <i32*> [#uses=1] %reg820 = load i32* %reg841 ; <i32> [#uses=1] ret i32 %reg820 }