397a98d86d
This change adds the new unroll metadata "llvm.loop.unroll.enable" which directs the optimizer to unroll a loop fully if the trip count is known at compile time, and unroll partially if the trip count is not known at compile time. This differs from "llvm.loop.unroll.full" which explicitly does not unroll a loop if the trip count is not known at compile time With this change "#pragma unroll" generates "llvm.loop.unroll.enable" rather than "llvm.loop.unroll.full" metadata. This changes the semantics of "#pragma unroll" slightly to mean "unroll aggressively (fully or partially)" rather than "unroll fully or not at all". The motivating example for this change was some internal code with a loop marked with "#pragma unroll" which only sometimes had a compile-time trip count depending on template magic. When the trip count was a compile-time constant, everything works as expected and the loop is fully unrolled. However, when the trip count was not a compile-time constant the "#pragma unroll" explicitly disabled unrolling of the loop(!). Removing "#pragma unroll" caused the loop to be unrolled partially which was desirable from a performance perspective. llvm-svn: 244467
114 lines
3.3 KiB
C++
114 lines
3.3 KiB
C++
// RUN: %clang_cc1 -std=c++11 -verify %s
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// Note that this puts the expected lines before the directives to work around
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// limitations in the -verify mode.
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void test(int *List, int Length) {
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int i = 0;
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#pragma unroll
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while (i + 1 < Length) {
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List[i] = i;
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}
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#pragma nounroll
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while (i < Length) {
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List[i] = i;
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}
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#pragma unroll 4
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while (i - 1 < Length) {
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List[i] = i;
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}
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#pragma unroll(8)
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while (i - 2 < Length) {
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List[i] = i;
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}
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/* expected-error {{expected ')'}} */ #pragma unroll(4
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/* expected-error {{missing argument; expected an integer value}} */ #pragma unroll()
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/* expected-warning {{extra tokens at end of '#pragma unroll'}} */ #pragma unroll 1 2
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while (i-6 < Length) {
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List[i] = i;
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}
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/* expected-warning {{extra tokens at end of '#pragma nounroll'}} */ #pragma nounroll 1
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while (i-7 < Length) {
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List[i] = i;
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}
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/* expected-error {{expected ')'}} */ #pragma unroll(()
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/* expected-error {{expected expression}} */ #pragma unroll -
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/* expected-error {{invalid value '0'; must be positive}} */ #pragma unroll(0)
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/* expected-error {{invalid value '0'; must be positive}} */ #pragma unroll 0
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/* expected-error {{value '3000000000' is too large}} */ #pragma unroll(3000000000)
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/* expected-error {{value '3000000000' is too large}} */ #pragma unroll 3000000000
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while (i-8 < Length) {
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List[i] = i;
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}
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#pragma unroll
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/* expected-error {{expected a for, while, or do-while loop to follow '#pragma unroll'}} */ int j = Length;
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#pragma unroll 4
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/* expected-error {{expected a for, while, or do-while loop to follow '#pragma unroll'}} */ int k = Length;
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#pragma nounroll
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/* expected-error {{expected a for, while, or do-while loop to follow '#pragma nounroll'}} */ int l = Length;
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/* expected-error {{incompatible directives 'unroll(disable)' and '#pragma unroll(4)'}} */ #pragma unroll 4
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#pragma clang loop unroll(disable)
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while (i-10 < Length) {
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List[i] = i;
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}
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/* expected-error {{incompatible directives 'unroll(full)' and '#pragma unroll(4)'}} */ #pragma unroll(4)
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#pragma clang loop unroll(full)
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while (i-11 < Length) {
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List[i] = i;
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}
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/* expected-error {{incompatible directives 'unroll(enable)' and '#pragma unroll(4)'}} */ #pragma unroll(4)
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#pragma clang loop unroll(enable)
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while (i-11 < Length) {
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List[i] = i;
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}
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/* expected-error {{incompatible directives '#pragma unroll' and '#pragma unroll(4)'}} */ #pragma unroll(4)
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#pragma unroll
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while (i-11 < Length) {
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List[i] = i;
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}
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/* expected-error {{incompatible directives '#pragma nounroll' and 'unroll_count(4)'}} */ #pragma clang loop unroll_count(4)
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#pragma nounroll
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while (i-12 < Length) {
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List[i] = i;
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}
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/* expected-error {{duplicate directives '#pragma nounroll' and '#pragma nounroll'}} */ #pragma nounroll
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#pragma nounroll
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while (i-13 < Length) {
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List[i] = i;
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}
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/* expected-error {{duplicate directives '#pragma unroll' and '#pragma unroll'}} */ #pragma unroll
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#pragma unroll
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while (i-14 < Length) {
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List[i] = i;
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}
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/* expected-error {{duplicate directives 'unroll(full)' and '#pragma unroll'}} */ #pragma unroll
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#pragma clang loop unroll(full)
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while (i-15 < Length) {
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List[i] = i;
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}
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/* expected-error {{duplicate directives '#pragma unroll(4)' and '#pragma unroll(4)'}} */ #pragma unroll 4
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#pragma unroll(4)
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while (i-16 < Length) {
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List[i] = i;
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}
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#pragma unroll
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/* expected-error {{expected statement}} */ }
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